Floods and mudslides caused by the downpours had killed six people and affected 304,853 residents from four cities and prefectures as of Monday, according to the provincial civil affairs department.
A total of 2,594 people were evacuated and more than 1,000 houses had been damaged or collapsed. About 10,242 hectares of crops were damaged as well.
According to rough estimates, the rainstorms caused direct economic losses of 30.9 million yuan ($4.8 million).
A new round of downpours will hit most parts of Guizhou from Thursday to Friday, the provincial meteorological center said.
In neighboring Hunan province, 19 cities and counties were battered by rainstorms lasting from Sunday morning to Monday.
As of noon Monday, 112,000 people had been affected and 26,000 people evacuated in Huitong county, which borders Guizhou province. The county is believed to have suffered direct economic losses of 230 million yuan.
About 5,666 hectares of crops were damaged and 2,050 houses were toppled, while traffic on national highways, power supplies and communication lines in the county have been disrupted by the rainstorms.
Rain-triggered floods also killed two people in Yushan county in East China's Jiangxi province last Saturday, the county government said.
As of 4 pm Monday, continuous rainstorms that began last Friday had affected 367,900 people and toppled 980 houses in Jiangxi, according to the provincial flood control and drought relief headquarters.