It was the latest in a series of similar incidents in recent years, including a fire at a hospital in the capital in 2023 that killed 26 patients and wounded dozens, Reuters reported.
Tuesday's fire in the city of Chengde in the northern province of Hebei blazed for two hours before it was doused, the official Xinhua news agency and the state-backed Global Times newspaper said, citing local authorities.
State broadcaster CCTV said police had arrested the owner of the apartment, while 19 residents of the home were taken to a nearby hospital for treatment and observation.
Experts are visiting the nursing home to ascertain the cause, Xinhua added.
In January, eight people were killed and 15 injured in a fire at a vegetable market in Hebei, while a department store fire in the southwestern province of Sichuan killed 16 people last year.