From April to May in 1998, time budget and behavior patterns of semi-free Cervus nippon were studied in Pingshan Wildlife Experimental Farm. The results showed that grazing behavior accounts the most for activity time in spring, next for ruminating and bedding behaviors, and the least for alerting and moving behaviors. In a day, there are three grazing peaks (namely, 7:00~10:00, 12:00~14:00 and 16:00~17:00). The female spend more moving time than the male do. The male spend more alert and bedding time than the female. C. nippong spend more grazing time in cloudy days than in fine and rainy days, whileC. nippon spends less alert and moving time in cloudy days. Sex and weather influence activity time budget of C. nippon. More significant differences exist between male and female's moving behaviors (F = 10.09,P < 0.01 ), while significant differences exist between bedding ( F = 5.96, P < 0.05) and alert ( F = 4.52, P < 0.05) be haviors. More significant differences exist between grazing ( F = 8.39, P < 0.01) and alert ( F = 6.11, P < 0.01 ) behav iors due to weather factor, while significant differences exist between bedding ( F = 4.27, P < 0.05) and moving ( F =5.32, P<0.05) behaviors.