Which ones?

Most of China's modern borders were formed fairly recently: during the Qing dynasty Tibet, Xinjiang, Mongolia and Manchuria were incorporated into the Qing empire whereas the preceding Ming dynasty had much smaller borders (http://imgur.com/ZbhElkk). The Qing lost outter Manchuria to the Russians in the 1860s. Upon the end of the Qing dynasty in 1911, the subsequent Chinese governments were able to keep all of the Qing Empire's territories with the exception of Mongolia and Taiwan.