The magnitude-7.2 quake hit at 6:33 a.m., about 225 140 miles southeast of the city of Hotan in southwest Xinjiang province, the U.S. Geological Survey reported.
China's Earthquake Administration confirmed the earthquake, but said it had a magnitude of 7.3.
There were no reports of casualties in the sparsely populated area, a spokesman for the agency said. The spokesman, reached at agency offices, declined to give his name.
There were four aftershocks in the region, ranging from magnitude 5.0 to magnitude 5.2, according to a notice on the Earthquake Administration's Web site.
The earthquakes occurred around Ahqan town and Bostan town, just north of the Kunlun mountains, with a total population of around 13,400 people, according to Chinese state media.
China's state-run television channel CCTV said some houses had collapsed, but that no one was hurt.
Xinjiang is a predominantly Muslim region with a culture that is distinctly different from that of China's ethnic Han majority.
Dale Grant, a USGS geophysicist, described the area as "very seismically active," and said Friday's temblor was the biggest there on record.
The Earthquake Administration said the last earthquake in the Hotan region in 1992 had a 5.9 magnitude.
A quake that hit western Xinjiang in 2003 had a 6.8 magnitude and killed 268 people in Bachu county.
Meanwhile, a moderate earthquake jolted an area of southwestern China close to the border with Myanmar, the official Xinhua News Agency reported.
There were no immediate reports of casualties or damage following the magnitude 5 quake in Yunnan province Friday night, the report said.
Phones at the seismological bureau in Yunnan's Yingjiang County were busy.
China's deadliest earthquake in modern history struck the northeastern city of Tangshan on July 28, 1976, killing some 240,000 people. Its magnitude was measured at 7.8 to 8.2.