The China Earthquake Networks Center said the 5.1-magnitude quake jolted the west part of northwestern province in the Haixi Mongolian and Tibetan Autonomous Prefecture, China's state-run news agency, Xinhua, reported.
Li Yuejin, deputy director of the Qinghai Provincial Seismological Bureau, said the earthquake occurred in a sparsely populated region of the province.
No deaths were reported, Xinhua said.
The 4.2-magnitude quake was reported in the Yushu Tibetan Autonomous Prefecture in the southern part of the province, the earthquake center said.
Xinhua said a casualty report was not immediately available.