Abstract: The paper made a survey of epidemiological analysi f syphilis invasion in Longquan City in 1992-1994.Thirteen cases were discovered in these three years with an annual rate of 1.65/100.000,surpassing that of the national morbidity.The cases mentioned in this paper are of early stage and the patients are mainly in socially active profession with a prportion of 76.97% and with the characteris-tic of obvious change in the attitude of sexual behavior.The education level of the patients are at or under the junior middle school with a proportion of 92.31%.Among the patients.61.54% had other STD.