To observe the effects of Yinxieling Tablet on the dynamic expression of leptin in the serum of obese patients with psoriasis vulgaris. Methods:A total of 60 patients with psoriasis vulgaris in Guangdong Provincial Hospital of Chinese Medicine from March 2017 to June 2017 were randomly divided into observation group (n=30) and control group (n=30). Control group patients were treated with compound clobetasol propionate ointment，and observation group patients received oral Yinxieling Tablets combined with the same external medication for two months. The efficacy of the two groups was observed and the dynamic expression of traditional Chinese medicine (TCM) syndromes score，skin lesion degree，body mass index (BMI)，and serum leptin were evaluated at one month and two months after treatment. Results:The effective rate of the observation group was 93.3%，which was significantly higher than that of the control group (73.3%，P<0.05). The scores of TCM syndromes，BMI and PASI of skin lesions in the two groups were significantly lower than those before treatment after treatment (P<0. 05). The serum leptin levels in both groups were lower than those before treatment (P<0.05). The serum leptin level after 2 months treatment was significantly lower than that at 1 month after treatment (P<0.05)，and the decrease of serum leptin level was more significant in the observation group than in the observation group (P<0.05). Conclusion:Yinxieling Tablets can significantly improve the clinical symptoms of patients and reduce the severity of psoriatic plaques and lower BMI. The mechanism may lie in regulating the metabolic state of the body by reducing leptin levels and decreasing IFN-γ level.