The U.S. Geological Survey says a magnitude-6.0 earthquake hit China's Xinjiang region about 60 miles (100 kilometers) from the city of Yining at 8:20 a.m. Tuesday, while the other quake struck the region bordering Sichuan and Gansu provinces at 6 a.m. at a magnitude of 5.5.
There were no immediate reports of injuries.
The earthquake in Xinjiang occurred at a depth of 17 miles (27 kilometers), while the other temblor was 10 miles (16 kilometers) deep.
China's worst quake in recent years was a 7.9-magnitude quake in Sichuan province in May 2008. It left nearly 90,000 people dead.