Abstract: From April 1998 to March 2001,the 24 hours time budget and activity rhythm of 5 captive Amur tigers (females and 2 males) were observed in Harbin Zoo,by all-occurrence and scan sampling methods.The results show that:There exist the d ifferences between the males and females in time budget and activity rhythm.The females spend more time sleeping and resting and less time moving and doing other behaviors than the males,but both sexes spend similar time eating.The males mainly sleep in the evening,and begin and end to move later 1 hour or so than the females.Variation of individuals and sexes,which were analyzed with one wa y ANOVA,indicates that there are clear differences in moving (P<0.05) among individuals,and in sleeping,resting,moving and other behaviors (P<0.05) between the male and female Amur tigers.