Objective To observe if fluoxetine has a potency to inhibit the progression of Lewis lung cancer by combining the fluoxetine and cisplatin to treat the mice bearing Lewis lung cancer with depression .Methods We devel-oped a mouse model of Lewis lung cancer with depression which was intervened with cisplatin and fluoxetine , and the indi-cators related to cancer and depression were tested .Social interaction test was used to measure the behavioral changes of the depressed model mice .The serum cortisol and IL-6, BDNF mRNA in the hippocampus , and NF-κB and VEGF in the tumor tissue were selected for investigation and comparison .Results The mice which were induced by social defeat exhib-ited social avoidance behavior in the social interaction test .The cortisol and IL-6 level in both combination groups was de-creased compared with that in the model group (P<0.05), and the cortisol and BDNF mRNA in the combination group in-creased signifuicantly ( P <0.05 ) .There were no statistically significant differences in the tumor weight , NF-κB and VEGF in tumor tissues between the single and combination groups (P>0.05).Conclusions Fluoxetine has antidepres-sant effect by decreasing the high level of serum cortisol and promoting the BDNF mRNA expression in the hippocampus . However , fluoxetine is not found to have the potency to inhibit the expression of NF -κB related with the progression of tumor.