The mating season of Giant Pandas ranges from January to June.

The female pandas may mate with more than one male in a single mating season to ensure successful fertilization.

In the female Giant Pandas, reproductive (oestrus) cycle commonly occurs once a year during months between January and June. During the cycle, there is a small window of time of 1 to 3 days when successful fertilization can take place and the female shows oestrous behaviour in allowing a male to mount and mate with her. The female may mate with more than one male panda to secure successful fertilization, which results in pregnancy.

The gestation period ranges from 83-163 days, 135 days is the average.

It is common to have 1 to 2 cubs in a litter. However, only one cub will receive enough care from the mother to survive. A panda cub is born blind, almost bold and completely helpless, therefore, it demands undivided attention, leaving the mother little or no time and energy to care for a second cub. To have three cubs in a litter is very rare.

A newly born cub weighs about 90g to130g (3-5 oz), in the order of 1/900th of the adult's weight.

A giant panda cub becomes independent of its mother at about 1 to 1.5 years of age. It leaves its mother's territory to establish his own and fends for itself. The female panda is then able to give birth again.