Objective: To compare the result of syphilis detected by RPR with that by TPPA and to acquire the information about the syphilis incidence in the Hengyang area during the past 4 years .Methods:Serum samples from the STD patients were detected for syphilis by RPR and TPPA. Tendency x 2 test was used for data analysis. Results:The detection rate of syphilis had year-increasing tend(x 2=15.070,P