Abstract: Objective To assess the prevalence of herpes simplex virus-1 (HSV-1) and herpes simplex virus-2 (HSV-2) among patients with sexual transmission disease and the phylogenetic characteristic of predominant HSV-2.Methods Totally 116 samples were collected from 16 outpatients from different areas in Jiangsu province.The TK gene of HSV-1 and HSV-2 were amplified,and the positive products were sequenced.After alignment with reference strain NC001798,the phylogenetic tree was constructed.Results Among 116 outpatients with sexually transmitted diseases,4 were HSV-1 positive with a prevalence of 3.5% and 36 were HSV-2 positive,with a prevalence of 31.0%.The virus sequences of HSV-2 from Su'nan region clustered together.The sequences of HSV-2 from Suzhong region also clustered except for SZ8.Conclusion HSV-2 was the major pathogen of genital herpes in Jiangsu province and the prevalence of HSV-2 was obviously different among various areas.