State broadcaster CCTV said one person died and six others were injured, including one seriously, in Baoxing county in Sichuan province. Other state media said three people were seriously injured.
The quake struck Lushan county, near the city of Yaan, at 5pm (0900 GMT) and was at a depth of 17km, the state television quoted China Earthquake Networks Center as saying.
The epicenter is 113 kilometres from Sichuan’s capital Chengdu.
According to Chinese newspaperThe Global Times over 200 rescuers have been dispatched to the epicentre.
An addition 1,100 rescuers are on standby across the province.
In 2013, Yaan was hit by strong earthquake, killing more than 100 people and injuring thousands.
More recently, a strong earthquake measuring about 6.9 on the Richter scale jolted a remote county in northwest China’s Qinghai province in January this year.
The 6.9-magnitude quake struck the mountainous part of the province at 1.45am, with an epicentre at 37.77 degrees north latitude and 101.26 degrees east longitude, according to the China Earthquake Networks Center (CENC).
Sichuan has a long history of earthquakes, with the most devastating having occured in 2008 when a magnitude-7.9 quake killed tens of thousands of people.
There were no immediate reports of injuries or damage from the quake and no tsunami warning was issued.
USGS reported that the quake occured around 220km below ground, at a depth which usually causes less damage than shallower seismic events.