Abstract: Objective To investigate the effects of TAT-OSBP-MKK6（E） on the tumor growth， invasion and metastasis of ovarian cancer xenograft in nude mice in vivo. Methods Eighteen female nude mice were randomly assigned to three groups： treatment group［TAT-OSBP-MKK6（E）］，negative group［TAT-OSBP-MKK6（E）+SB202190］and control group（saline only）.The cell lines were inoculated respectively into abdominal cavity of each group to establish intraperitoneal xenograft model of human ovarian cancer. Abdominal circumference were recorded every two days，the nude mice were sacrificed four weeks after inoculation. The ascitic volume， dissemination position number， disseminated tumor number， tumor weight and tumor growth inhibition rate were recorded. Histopathological characteristics for xenograft tissues were observed by hematoxylin and eosin（HE）staining. Cell apoptosis in tumor tissues was observed by TUNEL method and apoptotic index （AI） was calculated. The expressions of vascular endothelial growth factor （VEGF） and p38 in xenograft tissues were detected by immunohistochemical staining or Western blotting. Results Compared with the negative group and control group, the abdominal circumference growth in treatment group was delay with statistical significance （P＜0.05）.The treatment group had decreased in ascitic volume（P＜0.05），dissemination position number （P＜0.05）， disseminated tumor number（P＜0.05） and tumor weight（P＜0.05）， with tumor growth inhibition rate of 70.99％. the AI in the treatment group was（20.44±1.20）％，higher than （4.94±0.24）% of negative group and （4.00±0.79）% of control group, with statistical significance（P＜0.05）.The expression of VEGF in the treatment group （21.2％）was decreased compared to negative group（81.4％） and control group（85.7％）， with statistical significance（P＜0.05）. The relative expression of p38 was significantly increased in the treatment group （0.40±0.01） compared to negative group （0.22±0.01） and control group（0.20±0.01）， with statistical significance（P＜0.05）.Conclusion TAT-OSBP-MKK6（E） can significantly suppress the tumor growth, invasion and metastasis of human ovarian cancer in nude mice xenograft.