Establish the animal models of schizophrenia by using drugs effecting on glutamatergic systems such as phencyclidine, ketarnine, MK801... were considered by many researchers. The study to assess the subchronic effects of ketamine on social behaviors of monkeys as a basis for an animal model of schizophrenia in monkey. 8 monkeys (macaca mulusta, 4 males and 4 females, weighed 4 to 6 kg) were divided randomly into 4 pairs. Monkeys were injected with ketamine (dose 0.3 mg/kg/day, intramuscular) for 14 consecutive days. Locomotion and social behaviors of monkeys were analyzed before and after injection. Results showed that ketamine (dose 0.3 mg/kg/day, intramuscular) in monkeys increased locomotion after 10 minute injection. But it caused increased locomotion and reduced social interaction with others after 14 days consecutively. Present model investigated social interaction on monkey by using subchronic ketamine showed symptoms similar to the negative symptoms in schizophrenia patients.