Abstract:Ovulation and gestation are closely related to menstrual cycle. It is important to monitor the menstrual cycle of chimpanzees (Pan troglodytes) in captivity. This study analyzed the menstrual cycle records of 8 females reared in Shanghai Zoo since 2002 to 2017, and the data were analyzed by SPSS22.0. The luteinizing hormone (LH) in the urine of 2 female chimpanzees in a 60-day period was tested by using radioimmunoassay. The results showed that the average menstrual cycle was 33.5 ± 5.3 days; the average period of menstruation was 1.6 ± 1.1 days (Table 2); the average gestation period was 226.9 ± 17.3 days, with significant difference between the single and twins; LH surge appeared in estrus peak (Fig. 2).