Abstract: Investigations were carried out of status quo of the size, distribution and living of the breeding population of black-necked cranes in the Haizishan Nature Reserve of Sichuan Province in 2007-2010. One nest with two crane eggs and 56 cranes were recorded. Among them 51 were adult and 5 were young birds, accounting for 91.07% and 8.93%, respectively. The group of cranes scattered over gentle hills and lakes ranging from 4400 to 4556m in altitude. Breeding couples and chick-rearing groups were found mainly in shrub swamps and meadow swamps near lakes and rivers, and non-breeding groups in areas quite far apart from waters or in meadow swamps relatively high in landform. In 2009, interviews with inhabitants were conducted in 6 small townships in the Haizishan area. A total of 39 households, about 84.8% of the total visited, responded positively, reporting black-necked cranes were observed in 13 loci, e.g. Langcuo, Xixicuo, Xingyichuo, Chongchongcuo, etc. and nests and chicks were in 7 of the loci. In early April every year black-necked cranes migrate to the Haizishan Nature Reserve, where they begin to mate and breed, and leave for their wintering areas in late October. It is, therefore, held that Haizishan is a najor major breeding site for the central population of black-necked cranes and an important stop in the migration route of the birds.