Abstract: The sympatric coexistence of Ochotona cu rzoniae and O.daurica was found at Niannosoma area of Gangcha county, Q inghai province (is located 37°10'N. 49°40'E). In this area, we observed the behaviors of two pika species , and carried on a comparative study. 23 kinds of pika's behavior were desc ribed including 9 non-social behaviors and 14 social behaviors.For non-social b ehavior, the pattern of alert behavior of two pika species was different. O.daurica has hoarding behavior. O.curzoniae has mowing behavior ,this is different from those that lives in non-sympatric co-existent areas. 　　Non-social behavior of O.daurica comprised 95.85% of the all obs erved behaviors, non-social behavior of O.curzoniae comprise d 87.41%, the frequency o f non- social behavior was significant difference between two pika species (X 2=7.06,X2＞X20.01). Feeding is the most common non-social behavio r in two pika species. The second is alert behavior. O.curzoniae spent more time in alerting, and O.daurica spent more time in feed ing. 　　Social behavior of O.daurica comprised 4.14% of the all observe d behaviors, O.curzoniae's social behavior comprised 12.59% o f the all observed behaviors . There was significant difference on the frequency of social behavior between two pika species(X2=87.7,X2＞X20.01). O.curzoniae spent more time in social relation of interspecies. 　　In social behavior, affiliative behavior of O.curzoniae is the most common social behavior,it comprised 74.78% of the all observed social behav iors, the second is play-like behavior, the least is aggressive behavior,it com prised 9.90%. On the contrary,aggressive behavior of O.daurica i s the most common social behavior, it comprised 60.81% of the all observed soci al behaviors, the second is affiliative behavior,play-behavior is the least ,it comprised 5.41%. O.curzoniae is more social than O.daur ica, the social degree of O.curzoniae was higher than that of O.daurica, the attack character of individual in O.daurica population was stronger than that in O.curzoniae population.