Abstract： Objective To describe the clinical and epidemiological characteristics of psoriasis vulgaris in Liaoning region.Methods Five hundred and thirty-one outpatients with psoriasis vulgaris were surveyed by using a consensusly-designed questionnaire.EpiData3.1 and SPSS13.0 statistical softwares were used for data analysis.Results In the 531 patients with psoriasis vulgaris, the male to female ratio was 1.31: 1, and the average age at the first onset was 25.7±13.1 years.Guttate lesions were the commonest clinical manifestation,and observed in 49.5% of these patients.Lower limbs seemed to be the predilection site.The age at onset was younger in patients with family history than in those without(22.5±12.6 years vs.26.9 + 13.2 years, t=3.437,P＜ 0.05).The exacerbation of psoriasis vulgaris often occurred in winter or spring.Conclusions There seems no gender difierence in the development of psoriasis vulgaris, environmental and genetic factors appear to play an important role in the initiation and development of psoriasis vulgaris.