Objective The present study was designed to observe the effect of Wu You Decoction on behaviors of depressed rat model caused by chronic unpredicted mild stress，to explore its effect on depression. Methods 60 male SD rats were randomly divided into six groups：the normal control group，the model group，Venlafaxine group，the high，middle and low dose of Wu You Decoction groups. Establishing the depressed rat model by solitary raise combines with chronic unpredictable mild stress 21 days，then giving the medicines 21 days orally. To observe changes of behaviors of depressed rat by open field test and sugar consumption test and analyze the results. Results Wu You Decoction can improve obviously behaviors disorder of depressed rat model，Marked by increasing the score of horizontal and vertical movement of rats and incremental sugar consumption（P<0. 05）. Conclusion Wu You Decoction has effect of antidepressant.