ObjectiveTo explore whether reared baby or not influences the social behavior of female Macaca fascicularis raised in free enclosure. MethodsFrom May 2010, we randomly selected 40 monkey samples of the observation-available subjects from the rear base of Jiangsu Province Suzhou Zhongke Experimental Animals Co. Ltd. The formal observation was conducted from Oct 2010. Of the 40 female monkeys, 11 subjects reared baby and 29 subjects did not. Focal observation method using high resolution digital camera was employed by three trained observers to record the behavior of target subjects, 7 phases per day, 30 min per phase, and each subject was observed for 4 days, with a totally effective observation time 560 hours. The recorded video clips were randomly delivered to the Noldus analysis system with an analysis reliability kappa >0.8, and transferred into behavior data. ResultsThe subjects, who adopted baby, just hold the baby in most of time, more social amicable behavior, for instance, mutual grooming for others or being groomed by other companion, higher social rank, namely to share the rest place with monkey king on the board (which was hung across over the room) for longer time; more communication behavior, lip smacking; and more locomotive behavior and mating behavior with male subjects than those female monkeys not reared baby. Notwithstanding, the subjects who did not rear baby spent more time on embrace behavior with other companions. Otherwise, there were not significant differences on ingestive, rutting, rest, conflict, vigilance and miscellaneous behaviors. ConclusionThe reared baby has influence on the social behavior of female Macaca fascicularis.