Objective To observe the efficacy of Xiaotan Huayu formula in treatment of transient ischemic attack with hyper homocysteinemia (HHcy). Methods Sixty-four patients with transient ischemic attack (TIA) with HHcy were randomly divided into in treatment group and control group,32 in each. The control group received routine drug treatment,while the treatment group received Xiaotan Huayu Formula on the basis of conventional drug treatment.Treatment effect in the two groups was observed, and plasma Hcy concentrations before and after treatment were detected. Results Clinical total effective rate in treatment group and control group were 93.75% and 71.88% ,respectively, the treatment group was better than control group (P<0.05). Dropped more sharply Hcy in treatment group than in the control group (13.04±1.41) vs (17.27±1.47); the difference was statistically significant (P＜0.05). Conclusions Xiaotan Huayu formula is an effective formula in the treatment of transient ischemic attack.