The fire broke out at around 9.20pm on Tuesday in Shantou in Guangdong province and was put out about 40 minutes later, according to state news agency Xinhua.
The building was a four-storey reinforced concrete structure and about 150 square metres (1,600 square ft) were affected by the fire, local authorities said. An investigation into the cause of the fire is now under way.
The ground floor of the building has been turned into a store selling household appliances and electrical equipment, Chinese media platform Jiemian reported.
The area the house is situated in, Chaonan district, is a strong manufacturing hub with a number of small shops selling these goods or textiles.
A woman told the media on Wednesday morning that her parents, grandmother and younger brother had all died in the fire.
