This paper estimated the biomass and carbon storage and their spatial distributions of Qinghai spruce (Picea crassifolia) forests in Qilian Mountains, based on the field investigation, forest map, and meteorological data, and with the help of GIS technology. In 2008, the biomass of the forests was averagely 209.24 t x hm(-2), with a total biomass of 3.4 x 10(7) t. Due to the difference of water and thermal condition, there existed great differences in the biomass of Qinghai spruce within the Mountains. The biomass increased by 3.12 t x hm(-2) with increasing 1 degrees longitude and decreased by 3.8 t x hm(-2) with increasing 1 degrees latitude, and decreased by 0.05 t x hm(-2) with the elevation increasing 100 m. The carbon density of the forests ranged from 70.4 to 131.1 t x hm(-2), averagely 109.8 t x hm(-2), and the average carbon density was 83.8 t x hm(-2) for the young forest, 109.6 t x hm(-2) for the middle age forest, 122 t x hm(-2) for the near-mature forest, 124.2 t x hm(-2) for the mature forest, and 117.1 t x hm(-2) for the over-mature forest. The total carbon storage of Qinghai spruce forests in the study area was 1.8 x 10(7) t.