China's large but ageing fleet of submarines, including many acquired from Russia, is plagued by maintenance problems and the navy would struggle to mount a rescue if a vessel ran into difficulty, analysts have said.
Military experts said almost half of China's fleet of up to 50 submarines - including six which are nuclear-powered - are mothballed and have not been to sea for years.
Analysts doubt that China would ever admit to the loss of a submarine in an accident such as the Kursk's, and they said China would not have the expertise or equipment to instigate any kind of deep sea rescue.
"If there was a similar emergency to the Kursk, they would be in a much worse position," said an Asian military analyst, who asked to remain anonymous. "As far as any kind of rescue is concerned, I think the Chinese are much more backward than the Russians."
A Beijing-based Western military expert said China had never admitted to a single death in a submarine accident, and would never consider asking for international help.
"If an accident happened, we would hear nothing about it as, whatever the cause, it would be seen as showing up a weakness in China's military capability," the expert said.
The bulk of China's submarine fleet is made up of up to 40 Romeo-class conventional submarines bought from the Soviet Union and dating back to the 1950s, along with five Chinese built Han-class nuclear attack submarines.
China also bought at least four Kiloclass conventional submarines from Russia in the past five years, and is developing its own Song-class attack submarine.
The majority of the Soviet Romeo-class submarines are out of action, while two of the Kilo-class vessels ran into serious problems, the expert said.