Object : The aim of this study was to evaluate the changes of positive stmtoms. negative symptoms, and depressive symptoms after fluoxetine trial in haloperidol-stabilized schizophrenic in-patients. Method : Fluoxetine(20mg/day) was added for 6weeks to stable doses of haloperidol given to 32 schizophrenic in-patients. The subjects was divided into positive and negative schizophrenics by PANSS. The authors checked PANSS. HRSD at baseline, the 2nd week. the 4th week, the 6th week of treatment. Result were as follows : 1) In all subjects, positive and depressive symptoms were significantly improved. 2) As time went on, positive and negative symptoms were not significantly improved in positive and negative schizophrenics. 3) As time went on, depressive symptoms were not significantly improved in positive and negative schizophrenics. Conclusion : We suggested that fluoxetine may be useful in the treatment of positive symptoms in schizophrenia and, It may be due to the effect on the serotonin system and the interaction between serotonin and dopamine system.