Some houses collapsed, but there were no injuries, state media reported.
The 7.2-magnitude quake hit at 6:33 a.m. (2233 GMT Thursday), about 140 miles southeast of the city of Hotan in southwest Uighur province, according to the U.S. Geological Survey.
A spokesman for China's Earthquake Administration said it was a 7.3 magnitude quake. There were no reports of injuries, he said, and the area is sparsely populated.
There were four aftershocks in the region, ranging from 5.0 to 5.2 magnitude, according to a notice on the Web site of the administration.
The earthquakes occurred around the towns of Ahqan and Bostan, 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 that some houses had collapsed, but that no one was hurt.
Dale Grant, a USGS geophysicist, described the area as "very seismically active," but said Friday's temblor was the biggest there on record.
Uighur (Xinjiang) is a predominantly Muslim region with a culture that is distinctly different from that of China's ethnic Han majority.
China's Earthquake Administration said the last earthquake in the Hotan area struck in 1992, with a magnitude of 5.9.
In 2003, a 6.8-magnitude quake killed 268 people in Bachu county in the west of Uighur.
China's deadliest earthquake in modern history struck the northeastern city of Tangshan on July 28, 1976, killing some 240,000 people.
Last Mod: 21 Mart 2008, 15:44