The number of alpine musk deer has grown to more than 1,000 in a natural reserve in Northwest China's Gansu Province, making it Asia's largest captive breeding base for the endangered animals.

The Xinglong Mountain State Natural Reserve covers 4,667 hectares of land on a highland near Lanzhou, capital of Gansu. The number of musk deer has grown by almost 50 percent annually in the past four years, local officials said on Thursday.

The survival of wild alpine musk deer was threatened by poaching in the late 1990s after the market value of "musk oil" -- an extract from the animal's gland -- in traditional medicine rose, said Kang Fagong, a senior engineer of the reserve administration.

The natural reserve was set up in 2001 to protect musk deer from the poachers' guns, Kang said.