Abstract: Some biochemical parameters of seminal plasma were measured in twelve adult male rhesus monkeys (Macaca mulatta) in the breeding season. The results showed that the levels of fructose, novain，the activities of acid phosphatase and a-l，4 -glycosidase were 11.98±0.98g/L，319.82±65.61μol/L, (1.818±0.749)×10⁵ IU/L and 1. 76±0.46 1U/L respectively.