At least 47 people from 18 households were missing, state-owned China Central Television (CCTV) reported. Two of the missing people had been found dead in early Monday afternoon.
The landslide hit two villages in the southwestern city of Zhaotong at about 5:51 a.m. (2151 GMT), covering houses in brown mountain soil at the foot of a hill, state-owned China Central Television (CCTV) reported.
"The mountain just collapsed, dozens were buried," a man surnamed Gu, who witnessed the landslide, told the state-owned TV station for the neighbouring province of Guizhou. Gu said four of his relatives were buried under the rubble.
"They were all sleeping in their homes," he said.
Firefighters are climbing through the rubble searching for survivors in light snow, CCTV reported. It was not clear what caused the landslide.
China dispatched nearly 1,000 rescue workers to the scene, along with nearly 200 rescue vehicles, the report said. Chinese Vice Premier Zhang Guoqing was leading a workgroup to the site to guide rescue works.
More than 500 people have been evacuated from their homes.
Yunnan is among several provinces in the country's southern region currently experiencing bitterly cold temperatures, according to the National Meteorological Centre.
