OBJECTIVE： To observe clinical efficacy and safety of citalopram in the treatment of depression patients after lung cancer operation. METHODS： 114 depression patients after lung cancer operation were selected and randomly divided into observation group and control group （n＝57）. Control group was given routine treatment as nutrition support and electrolyte balance， but had no anti-depression drugs； observation group was given Citalopram tablet 20 mg orally， qd. Two groups were treated for 6 weeks. Clinical efficacy， HAMD and HAMA scores， each score and total score of SF-36 were observed before and after treatment. The occurrence of ADR was recorded. RESULTS： The total effective rate of observation group was 87.72％， which was significantly higher than that that of control group （71.93％）， with statistical significance （P＜0.05）； there was no statistical significance in HAMA score， HAMD score， each score and total score of SF-36 between 2 groups before treatment （P＞0.05）； HAMA score and HAMD score of 2 groups decreased significantly after treatment， the observation group was lower than the control group； each score and total score of SF-36 increased significantly， the observation group was higher than the control group， with statistical significance （P＜0.05）. No obvious ADR was found in 2 groups. CONCLUSIONS： Citalopram is effective and safe for depression after lung cancer operation， can improve mental state and quality of life.