Abstract: Based on 11 anatomic specimens,including 7 for Francois leaf monkeys Presbytis f.francoisi (2 males and 5 females),P.f.leucocephalus (1 female,and 3 for Phayre s leaf monkeys P.phayrei) (3 females),musculature of the upper and lower limbs of two leaf monkeys were studied and compared with those in other primates.The results showed:in regard to most myological characteristics two leaf monkeys share plesiomorphous ones with Cercopithecoidea,and some of them are similar to that of the anthropoids.However,there also exist some differences compared with the monkeys.