Officials and state media said 17 people were confirmed dead and 44 others were missing after torrential rains sent landslides crashing into villages in southwestern China on Tuesday.
Chinese meteorologists predicted more heavy rains over the next three days.
Nearly 400 people died after heavy rains in June.
Since the beginning of July, some 29 million people over nine provinces have been affected by the rains and 997,000 have been evacuated.
About 42,000 houses have collapsed and another 121,000 damaged, the ministry added.
Hundreds of thousands of hectares of crops have been affected as well, with economic losses estimated at $17bn, state television said.