Objective Observe the effect and security of venlafaxine in obsessive-compulsive disorder(OCD) treating.Methods Forty-five OCD patients were divided into venlafaxine group(23cases) and clomipramine group(22cases),and they were observed by Y-Bocs and TESS in 8 weeks.Results 1.The effect between two groups was similar,and the venlafaxine worked by 65.2%,while the clomipramine 72.2%(P0.05).2.There was positive correlation between effect and course of disease.Short course of disease,good effect.3.Gender difference:male had better effect than female.4.Side-effect(TESS):venlafaxine was lighter than clomipramine,and was temporary,endurable.5.Venlafaxine worked fast and was good at loosing obsessive thoughts,while clomipramine was good at loosing obsessive behavior.Conclusion Venlafaxine is effective to OCD,especially on obsessive behavior.It works fast with light side-effect and male or short course of disease will have better effect.