The cub was born at Penglai Ocean and Polar Region World, an aquarium in China's eastern Shandong Province.
She only weighs a little over 1 pound and is being kept in an incubator.
Despite suffering from malnutrition and problems with her digestive, respiratory and nervous systems, the bottle-fed cub is no longer in critical condition.
The aquarium's staff expects her to make her first public appearance in about six months.
In the wild, polar bears usually live into their early teens. In captivity, they can live up to 35 years.
According to the U.S. Fish and Wildlife Service, the polar bear is the world's largest land predator. There are around 20,000 to 25,000 polar bears in the wild.
ABC News contributed to this report.