The blue sheep (Pseudious nayaur) is the major large-size herbivores in Helanshan. During studying, the blue sheep mean group size were 4.2¡ã7.1, with smaller group size than in other ranges. Mixed groups were usually bigger than male and female groups. Sex ratio the most close was 1:1.08 (¡ð:¡ñ) in winter, and other samples still favored males except for fall. The highest ratio of adult female to young was 1:0.78 in summer. In daily activity cycle, blue sheep usually moved and fed in morning and evening, but rested during noon. In summer, animals started active earlier and ended latter than in winter, but had more short active time. From summer to fall, the blue sheep mostly used the edge of forest and used forest least in altitude 2200m. But in altitude 1700m, blue sheep used grassland more than frequently bush and fountain.