Dispersal, the movement from a natal/breeding site to another breeding site, has been suggested to reduce the inbreeding and/or enhance the reproductive success. In rhesus macaques (Macaca mulatta), females remain in their natal groups throughout their lives, while males migrate around puberty. In order to test the function of dispersal in an endemic subspecies of rhesus macaques in China, we analyzed the paternity of newborn offspring which could be used to estimate the reproductive success of the immigrant and natal adult males.