At least 89 people were confirmed dead in Sichuan province where 41 people remained unaccounted for, the provincial disaster relief office said on Wednesday.
In neighbouring Chongqing, the death toll rose to 54 with 16 missing and more than 550 injured.
Officials said most of the deaths were caused by landslides, mud and rock flows and flash floods sweeping through mountain valleys.
Heavy rain has been pounding the area since last Thursday but eased on Tuesday as rescue teams took to boats to try and reach people cut off by floods and torrents of mud.
Provincial and municipal officials were also working to resume water and power supplies and restore transportation and telecommunication facilities.
"There have been a lot of heavy mud slides and landslides. It is a serious situation in some counties," said the Sichuan official.
"In Xuanhan county in Dazhou city there are around 3000 people trapped by mudslides. In that city around 10,000 are trapped altogether. Local officials and troops are trying to evacuate people living in dangerous places."
The rains have caused cave-ins on urban roads and destroyed main roads out of the city, which has been drenched by 360 millimetres of rain.
"It is still raining but it is light. The weather is better," she said.
Disaster relief officials said more than 450,000 people have been evacuated from the storms, which have damaged or destroyed 127,000 homes and 400 bridges, and washed away at least 720 kilometres of roads.
Thousands of hectares of farmland have also been ruined.
"It is still raining but it's not heavy, we don't expect any more serious disasters. In many places the water levels are declining," said He from Chongqing.
The rains in China have destroyed
homes, roads and power supplies
"We have 30 rescue boats operating trying to reach people trapped by floods."
Like Sichuan, landslides triggered by torrents of water gushing down mountain sides were also widespread in Chongqing.
"For example, in Yunyang county there have been 23 landslides and we are still gathering more information from other countries and districts," said He Lingyun.
"It's difficult to forecast what will happen now, whether there will be more casualties."
Kai district in Chongqing has borne the brunt of the weather with municipal mayor Wang Hongju saying many water conservancy facilities had been damaged and 84 schools were flooded, affecting 40,000 students.
"All the injured have received timely and effective treatment and they are out of danger now," Shu Ya, director of the county's health department, was quoted as saying by Xinhua news agency.
He said medical teams had been rushed to the flooded areas to minimise the chances of disease.
The central government has announced 40 million yuan (4.8 million dollars) in urgent aid for people "who have trouble meeting basic needs" in the rain-hit regions, according to state television.