The shaking wrecked more than 4,000 houses and cut off communications with parts of Ninglang county in Yunnan, according to the official Xinhua news agency.
It also killed more than 1,200 domestic animals, officials said.
The region is inhabited by a large number of people belonging to the Yi ethnic group.
The Chinese government said the quake had a magnitude of 5.5 when it struck just seconds before 4:00 p.m. local time at a depth of about 9 miles.
Scores of aftershocks kept nerves on edge and people sleeping outside for two days following the initial jolt.
An 8.0-magnitude quake rocked Sichuan on May 12, 2008, killing tens of thousands of people and flattening buildings across a wide swath of the province.