The animal was born to brown yellow African lions, but is white because of a rare colour mutation.
Manager Zheng Yundong said he was shocked at the discovery. He said: "At first I was surprised as the chance to have a white lion is quite small. Someone said it is a throwback, while some others said it is an evolution."
A mother dog (a circus dog) was acting as the lion cub's wet nurse after its own mother failed to produce enough milk of her own.
"The mother lion can only produce milk one day after giving birth, and if the cub doesn't suck milk for eight hours, we have to take it under our wing, which was the case for yesterday," explained Mr Zheng.
White lions are not classed as a separate subspecies.