China began to build a fourth giant panda breeding base in northwestern Shaanxi Province Friday, which is expected to add at least eight cubs to the population of the endangered species a year.

With an investment of 69.54 million yuan (10.2 million U.S. dollars), the Qinling giant panda breeding base will cover 287 hectares, according to Zhang Shenian, head of the provincial forestry department.

The base will have eight breeding pens and 10 "kindergartens" for cubs, and the 22 pandas which will live there after the base is built are expected to have at least eight cubs a year, and the total population of the base could reach 40 in two years, according to Zhang.

There are about 1,600 giant pandas living in the wild, mostly in southwestern Sichuan Province and the northwestern provinces of Shaanxi and Gansu.

The Qinling subspecies of giant panda in Shaanxi has smaller but rounder heads than the Sichuan subspecies. A total of 273 Qinling giant pandas now live in their 606,800-hectare habitat.

The previous three breeding bases are in Sichuan's capital Chengdu, and the famous Wolong Nature Reserve, also in Sichuan, and the Beijing Zoo.