Abstract: The faunal composition of butterflies in different habitat types in the Qilian area of Qinghai Province , northwest China , was surveyed f rom 1997 to 1999. Five habitat types were classified based on altitude , climate , soil and vegetation differences : hilly cultivated land , mountain steppe , forest steppe , alpine shrub meadow and bare rock. Of the total collection of 4 ,367 specimens , 53 species of 35 genera in six families were identified. Species richness , species composition similarity (J accard index) and species diversity index ( Shannon-Wiener index , H′) were calculated for the five habitat types. The species richness increased in the following sequence : bare rock (6 spp. ) , mountain steppe (13 spp. ) , forest steppe (14 spp. ) , alpine shrub meadow (22 spp. ) and hilly cultivated land (23 spp. ) . In cont rast , the species diversity increased in a different sequence : bare rock ( H′= 1.4629) , forest steppe ( H′= 2.2398) , mountain steppe ( H′= 2.2676) , hilly cultivated land ( H′= 2.7071) and alpine shrub meadow ( H′= 2.7734) . The butterfly species composition between forest steppe and hilly cultivated land had the highest similarity (J accard index = 0.3704) , with the second highest similarity between mountain steppe and alpine shrub meadow (J accard index = 0.2500) , and the lowest similarity between bare rock and other habitat types.