The People's Republic of China came into existence in 1949 when the communist party, after a bloody civil war ousted the American supported General Chiang Kai Shek. The Chinese aircraft industry at that time was non-existent and the Russians under Stalin supplied the MIG-15 to the fledgling PLAAF. In 1956, due to an ideological shift the Russians withdrew their advisors and China was left to fend for itself. The Chinese did some reverse engineering and made clones of the Russian MIG-15 and MIG-17.
Military hardware from Russia
Things changed after the collapse of the Soviet Union and from 1990 onwards the cash-starved Russian government restarted sale of aircraft and #military hardware to China. The Russians sold military equipment worth billions of dollars to China, which was desperate to modernize its military so as to face the USA and Japan in the East and India in the south.
The Russians also inked a deal to Supply the SU-27 advanced air superiority fighter. The Chinese reportedly paid $1 billion for 24 SU-27s. This was in 1992 and in 1996, the Chinese signed a contract to build 200 SU-27s in China under license. This deal was for $2.5 billion. At that time the Russians did not pay much attention to proprietary rights.
The Russians had not gauged the Chinese mind correctly, as after producing 104 of these state of art machines, the Chinese canceled the contract on the plea that the plane did not serve Chinese interests.
Chinese engineers secretly reverse-engineered the SU-27 and produced their own supersonic fighter the J-11B. This was a surprise to all and showed the world that Chinese technology was good at copying other nations aircraft. The 11B is identical to the SU-27 and China is keen to sell it to other nations. The plane earlier had Russian engines, but the latest versions have Chinese engines, which are clones of the Russian engine.
Cloning of Russian plane
The Chinese plane has similar statistics to the Russian supersonic fighter and has a speed of Mach 2.35 and a range of 3,200 miles. It's a clone of the Russian plane. The Chinese have developed their own indigenous radar and the plane can simultaneously engage 4 enemy aircraft. The development of the J-11B is a coup for China and a warning to the USA that China could flex its muscles in the South China Sea. The Chinese have a problem in Tibet in facing the IAF as the Chinese planes efficacy is reduced by 50% because of the operations at a height of close to 10,000 ft.