Classic Chinese Nuclear Submarines

The first Chinese nuclear submarines were two submarines of the Han Class, the designs of which were copies of Russian SSNs. During the Cold War the Han class was China's main attack submarine for defending her shores. After China became a nuclear power in the 1970s China developed the Xia Class SSBN to launch ballistic missile attacks. Xia is interesting because the entire weapon system including its SLBMs (Submarine Launched Ballistic Missiles) are all indigenous.

 An entry on the Han Class from the World Encyclopedia of Submarines by John Parker. 

An entry on the Xia Class from the World Encyclopedia of Submarines by John Parker. Note that the book discusses plans for new Chinese submarines and how those might affect American interests.