Abstract: The adult Macaca mulatta from the Taihang Mountains had been measured about seventeen variables of the mandibles （male 9，femal 16）. Employing SPSS for windows 10.0，ANO-VA test showed that only three variables are significant differences between sexes. Sexual discriminant functions were constructed by means of Enter independents together and Use stepwise method. The results showed： the discriminant rate of the former is 100%，and the latter is 88.0% . But the latter is simpler.

Key words: Rhesus macaque, Mandible, Sex difference, ANOVA, Discriminant analysis