The heavy rain, which started on Tuesday, has affected 26 counties in Jiangxi, the provincial flood prevention and drought control headquarters said.
Local governments have relocated 6,019 residents to avoid potential risks, state-run Xinhua news agency reported.
The downpours have also damaged or destroyed 202 houses and ruined 16,710 hectares of crops, as well as causing high water levels of rivers and lakes, and several landslides.
Flood prevention authorities in Jiangxi warned of floods on Thursday due to the rising rivers and lakes.