China to expand submarine fleet toward 70 boats by 2027 and 80 by 2035 to challenge US Navy.

China could expand its submarine fleet to about 70 boats by 2027 and around 80 by 2035 according to U.S. naval intelligence assessments.

U.S. naval intelligence indicates China could expand its submarine fleet to about 70 boats by 2027 and around 80 by 2035, including new nuclear-powered attack submarines, guided missile submarines, and ballistic missile submarines. These new submarines would significantly increase China's naval presence across the Indo-Pacific and affect the maritime balance with the U.S. Navy.
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Current projections indicate the Chinese submarine fleet could reach roughly 80 submarines by 2035, with about half powered by nuclear reactors to increase the country's endurance and operational reach across the Indo-Pacific. (Picture source: Chinese MoD)

On March 2, 2026, Rear Admiral Mike Brookes, from the U.S. Office of Naval Intelligence, highlighted a rapid expansion of China's undersea forces, indicating that its submarine force could reach roughly 70 submarines by 2027 through the addition of six nuclear-powered guided-missile submarines, three smaller-class nuclear-powered attack submarines, and two ballistic missile submarines while retiring older Chinese and Russian-built units. Continued construction could expand the inventory to about 80 submarines by 2035, with roughly half of the fleet powered by nuclear reactors, representing a major shift in force composition toward longer-endurance vessels. Projections for the early 2040s indicate the possible addition of 20 to 30 new-class nuclear-powered guided-missile and ballistic missile submarines designed for blue-water operations beyond the first island chain.

Parallel investments are directed toward unmanned underwater vehicles, seabed sensor networks, and oceanographic mapping, intended to improve submarine detection and maritime area control. These would significantly expand China’s capacity for sea denial, strategic deterrence patrols, and long-range strike operations in the Indo-Pacific maritime theater. Undersea warfare now forms a central component of Chinese naval strategy across multiple operational missions, including strategic nuclear deterrence, sea-lane interdiction, intelligence collection, and precision strike against naval and land targets. For now, more than 60 submarines operate as part of the People’s Liberation Army Navy to secure maritime approaches in the East China Sea and South China Sea while extending naval reach toward the western Pacific and beyond.

This fleet is part of China's operational framework named “Near Seas Defense, Far Seas Protection,” which combines coastal defense with the ability to conduct distant maritime operations. Underwater capabilities support both defensive tasks, such as protection of ballistic missile submarine patrol areas, and offensive missions, including attacks on surface vessels and logistics routes. Chinese naval planning also emphasizes integration of submarines with air assets, surface combatants, seabed sensors, and satellite-linked surveillance networks. This integrated structure aims to monitor critical maritime corridors and reduce the freedom of maneuver of adversary submarines operating near Chinese waters.

China’s current submarine fleet includes several distinct categories of vessels with different operational roles. Nuclear-powered attack submarines include the Type 093 Shang-class, with newer Shang III variants incorporating ducted propulsors and improved acoustic quieting. At least six of eight expected Shang III submarines have been launched since 2022, and these boats feature vertical launch systems capable of firing anti-ship and land-attack cruise missiles. Nuclear-powered guided-missile submarines, such as the future Type 095 Sui-class, provide long-range precision strike capability and are intended to launch cruise missiles against maritime and land targets. Nuclear-powered ballistic missile submarines include the Type 094 Jin-class, which carry JL-3 submarine-launched ballistic missiles capable of targeting intercontinental distances while operating within bastion areas near the first island chain.

China also operates more than 50 diesel-electric submarines, including Type 039A/B Yuan-class boats equipped with air-independent propulsion systems that increase submerged endurance and reduce exposure during snorkeling operations. Industrial development has played a central role in expanding the Chinese submarine construction capacity. China operates three major submarine shipyards where large infrastructure investments have expanded construction halls and increased assembly space for submarine production. These upgrades have more than doubled submarine production capacity and allow simultaneous construction of multiple submarines with larger hull diameters and modern reactor systems.

Production rates for nuclear-powered submarines have increased from less than one boat per year to significantly higher levels as facilities expand manufacturing throughput. Shipyard modernization includes upgraded fabrication facilities capable of building larger pressure hull sections and integrating advanced sonar arrays and propulsion systems. Increased industrial capacity supports the steady production of both nuclear-powered submarines and conventional diesel-electric boats while enabling the introduction of next-generation submarine classes. Sustained construction programs are expected to maintain fleet expansion through the 2030s. Next-generation submarine programs focus on improved propulsion, reduced acoustic signature, and expanded missile capabilities.

For instance, the Type 095 nuclear-powered guided-missile submarine is designed for long-range strike missions and incorporates improvements in nuclear reactor efficiency, sensor systems, and noise reduction technologies. The Type 096 ballistic missile submarine represents the next generation of China’s sea-based nuclear deterrent and is expected to carry JL-4 submarine-launched ballistic missiles capable of striking large portions of the United States from patrol areas near Chinese coastal waters. Earlier modernization programs produced the Shang III attack submarine equipped with a 24-cell vertical launch system that allows the launch of cruise missiles against maritime or land targets. These new submarines will soon expand China’s long-range strike capability from submerged positions.

For now, existing Jin-class submarines equipped with JL-3 missiles already enable deterrence patrols without requiring transit into distant ocean patrol areas. Changes in force composition indicate a gradual transition toward a larger nuclear-powered submarine fleet. Current projections indicate the fleet could reach roughly 80 submarines by 2035, with about half powered by nuclear reactors, increasing endurance and operational reach. Nuclear propulsion allows extended underwater operations without refueling and enables deployments across larger maritime distances compared with diesel-electric boats. Development programs include the Type 041 Zhou-class nuclear-powered attack submarine, a smaller reactor-powered design roughly comparable in size to conventional submarines but capable of longer patrol durations.

This may support regional patrol missions where full-size nuclear submarines are not required. As older diesel-electric submarines are gradually retired, new nuclear-powered submarines are expected to form a larger proportion of the fleet, extending deployments in the western Pacific and potentially other ocean regions. China is also developing a wide range of unmanned underwater systems (UUVs) designed to support reconnaissance, seabed mapping, mine warfare, and strike operations. Autonomous underwater vehicles such as the HSU001 conduct intelligence, surveillance, and reconnaissance missions and can collect oceanographic data that improves sonar performance. Other systems, such as the AJX002, are designed for missions including mine placement and potentially torpedo delivery.

Concept vehicles such as the UUV300 incorporate modular payload bays capable of carrying sensors, torpedoes, mines, or deployable, smaller autonomous vehicles. Long-endurance underwater gliders gather oceanographic data, including water temperature, salinity, and currents, to support acoustic modeling and submarine detection. These systems can operate independently or in coordination with manned submarines, increasing underwater surveillance coverage while reducing risk to crewed vessels. Seabed surveillance systems form another component of China’s expanding undersea infrastructure. The Blue Ocean Information Network integrates seabed sonar arrays, underwater sensor nodes, satellite-linked buoys, and mobile autonomous underwater vehicles into a layered maritime detection architecture.

These assets collect hydrographic data that supports submarine tracking and improves acoustic detection accuracy in areas such as the South China Sea. Surface vessels equipped with towed-array sonar systems and embarked anti-submarine warfare helicopters expand detection capability above the water column. Small-waterplane-area twin-hull catamaran vessels support reconnaissance and surveillance missions and provide stable platforms for sensor deployment. The combination of seabed sensors, mobile surveillance assets, and autonomous underwater vehicles supports continuous monitoring of key maritime chokepoints and shipping routes. Therefore, the expansion of China’s submarine fleet, combined with advanced sensor networks and autonomous underwater vehicles, increases the scale and persistence of Chinese underwater operations.

Submarines designed for blue-water missions could extend patrols beyond the western Pacific into the Indian Ocean and Arctic approaches, with possible deployments in the Atlantic during the 2030s and 2040s. Greater numbers of nuclear-powered submarines increase the ability to conduct long-duration patrols and maintain a continuous presence in distant maritime areas. At the same time, expanded surveillance networks increase the capacity to detect and track submarines operating in contested waters. The combination of submarine modernization, unmanned systems, and seabed sensing technologies indicates that the undersea domain will remain a central area of strategic military competition with the U.S. in the coming decades.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.