Officials said at least 53 people were killed and more than 60 injured when fire broke out on the second floor of the busy four-storey Zhongbai Commercial Plaza in the north-eastern city of Jilin, which housed shops, a dance hall and a bath house.
Most of the victims were customers on the third and fourth floors enjoying baths and billiard games, an official at the Jilin city government told Reuters.
"Shoppers on the second floor where the fire started were pretty lucky because they were able to run away," he said by telephone.
Authorities were still investigating the cause. The official Xinhua news agency said a preliminary investigation indicated the fire started in a temporary storehouse near a boiler room.
A separate fire tore through a temple full of pilgrims in the city of Haining in eastern China's Zhejiang province, killing 39 worshippers and injuring four, Xinhua said. It was put out after about 30 minutes.
No further details were immediately available.
Witnesses to the Jilin mall fire said many people, bundled in thick coats against the sharp cold, jumped from top floors.
Wooden boards which were used to carry the dead and injured later lay strewn around the centre, wet with blood.
An official at Jilin's Central Hospital told Reuters many of the injured suffered from smoke inhalation or shattered their legs when they hit the ground after leaping.
"There are many leg injuries because they jumped," he said by telephone. "Today was Sunday, so the mall was packed with weekend shoppers."
The fire was believed to be China's most devastating accident so far this year, Xinhua said. Built in the 1990s, the shopping centre held 111 shops and covered around 4,000 square metres.
A fire on December 25, 2000 killed 309 disco revellers and construction workers at a dance hall in a commercial centre in the Chinese city of Luoyang. In 1994, 325 people, 288 of them children, died in a concert hall fire in the oil town of Karamay.
Xiao Yao, a manager of the Jilin shopping mall, told Reuters that fire-fighters and officials were mopping up after the fire: "The building is virtually black now and the fire-fighters have withdrawn," he said.