Abstract: Grassland resource investigation by the combination of 3S technique, fixed-sampling site and route survey was carried out in Sunan county. The grassland type, area, distribution and species composition were determined; and the plant coverage, height and field were measured. 1) The grassland in Sunan county was divided into 9 classes embracing 18 subclasses, the 29 types of 24 forms; the total area of grassland was 1 778 729 ha in Sunan county. 2)Sunan county did not have the 1,2,3 and 4 grade grassland, alpine steppe was the 5 grade grassland with an area of 424 614 ha, which accounted for 23.87% of the total area of grassland in Sunan county, the average fresh grass yield was 3 685 kg/ha; alpine meadow, temperate steppe, temperate steppe-desert, temperate meadow-steppe and alpine steppe was the 6 grade grassland with an area of 883 145 ha, which accounted for 49.65% of the total area of the grassland, the average fresh grass yield was 2 577, 2 565, 2 508, 1 880 and 1 820 kg/ha respectively; temperate desert, temperate desert-steppe and lowland meadow was the 7 grade grassland with an area of 470 966 ha, which accounted for 26.47% of the total area of the grassland, the average fresh yield was 900, 1 167 and 1 137 kg/ha respectively. 3) The total fresh grass yield in Sunan was 4 260.544 3 million kg, which converted into 1 460.616 1 million kg wind-dried grass, the theoretic grazing capacity in the natural grassland should be 1.064 1 million sheep-units; at present, the livestock in Sunan was 102 million sheep-units converted, which basically was in the saturation. 4) The Qilianshan Mountains have abundant and rare animal and plant resources, it is identified that among the 749 species of 986 pieces of plant samples collected during the investigation, 16% of the plants were from Compocitae, 14% plants from Poaceae, 8% of plants from Liguminosae, 6% of plants from Cyperaceae, 6% of plants form Raunuculaceae, 5% of plants from Rosaceae, 3% of plants from Cruciferae, 3%of plants from Chenopodiaceae, 3% of plants from Liliaceae; the plants from other families accounted for 35%. The Qilianshan Mountains have 286 species of wild animal, which belonged to 63 families of 28 orders, among which class Pisces had 4 species of 2 families from 1 order, class Reptilia had 5 species of 3 families from 2 orders, class Amphibia had 2 species of 2 families from 1 order, class Aves had 206 species of 39 families from 17 orders, class Mammalia had 69 species of 17 families from 7 orders. Out of the wild animals, 9 species were the first class national protected animals; 39 species were the second class national protected animals.