Group characteristics of dwarf blue sheep (Pseudois schaeferi) were studied with line transect method and fixed-point observation method in Zhubalong Nature Reserve of Sichuan Province during winter (in 2007，2008) and spring （from March to May in 2009）. Among the individuals of the dwarf blue sheep observed, a total of 73 groups including 451 individuals of dwarf blue sheep were accumulatively observed in spring and 170 groups including 1036 individuals in winter. The maximum group observed including 34 individuals, and the mean group size was (6.18±5.186) in spring. The maximum group observed including 24 individuals in the winter and the mean group size was (6.65±4.564). The mean group size had no significant difference between spring and winter (P>0.05). Mixed group was the main group type in winter, and the frequency was 57.20%. The mixed group and the mother-baby group were the main group types in spring, and the frequency were 45.20% and 26.03% respectively. Compared to spring, the mixed group and the solitary occupied higher frequency in winter. However, the main types in spring were the female group and the mother-baby group. Mann-Whitney U tests indicated that during different seasons, the changes of group size of mixed group, female group were not significant (both P >0.05). But the size of the male group（P < 0.05) and the Ewe-lamb group(P<0.05) change significantly; Chi-square criterion indicated both in spring and winter, the group sizes among different group types of dwarf blue sheep were pole significant（P <0.01） Kruskal-Wallis H tests indicated that the differences group types were not significant（P >0.05）between spring and winter. The solitary were seldom seen in both winter (15 times) and spring (2 times), including thirteen males and two females in winter, two females in spring, with the frequencies 8.82% and 2.74% respectively; dwarf blue sheep were frequently seen in small herds of 2 to 8 individuals, with the frequencies of 64.12% in winter (165 times) and 76.71% in spring (56 times). The frequencies of the group more than 9 individuals were 22.73% in winter (46 times) and 20.55% in spring (15 times) respectively. Our findings indicated that the groups with 2-8 individuals were most common. Among the individuals observed, there were 607 adults (236 males, 271 females), 143 sub adults and 286 kids in winter, with the frequencies 58.59%, 13.80% and 27.61% respectively. Meanwhile, there were 274 adults including 115 males and 159 females, 49 individuals of sub adults and 128 individuals of kids in spring, and the frequencies were 60.75%, 10.87% and 28.38% respectively. The percentage of the audit was more and the percentage of sub adult and kid were small in winter and spring; the ratio of female-male was 1∶0.72 in spring and 1∶0.64 in winter, The ratio of female-juvenile was 1∶0.81 in spring and 1∶0.77 in winter. The results indicated that in winter, the both ratio of female-male and female-juvenile were fewer than spring.