OBJECTIVE： To investigate the clinical efficacy and safety of mirtazapine combined with citalopram in the treatment of sleep disorder in depressive patients. METHODS： One hundred and sixty-five depressive patients with sleep disorder were selected and divided into control group （82 cases） and treatment group （83 cases） according to random number table. Control group took Escitalopram oxalate tablet 10 mg， once every night， increasing to 20 mg according to disease condition； treatment group was additionally given Mirtazapine tablet 15 mg， once every night， increasing to 30 mg one week later. Both groups received treatment for consecutive 6 months. HAMD-17 and MADRS were observed in 2 groups before and after treatment， and the sleep quality of 2 groups were evaluated by PSQI before and after treatment； the sleep structure was measured by using polysomnography before and after treatment； clinical efficacies and the occurrence of ADR were compared between 2 groups. RESULTS： Before treatment， there was no statistical significance in HAMD-17， MADRS and PSQI score， sleep structure between 2 groups （P＞0.05）； after treatment， above scores and indexes of 2 groups were all improved significantly， and the treatment group was significantly better than the control group， with statistical significance （P＜0.05）. Total response rate of treatment group was 97.47％， which was significantly higher than 78.95％ of control group， with statistical significance （P＜0.05）. There was no statistical significance in the incidence of ADR between 2 groups （P＞0.05）.  CONCLUSIONS： Citalopram combined with mirtazapine shows significant therapeutic efficacy for sleep disorder of depressive patients， and can significantly improve sleep structure， adjust sleep cycle and improve sleep quality with good safety.