Objective To analyze the false-positive results of Treponema pallidum antibody caused by 3 different assay in comparison with Treponema pallidum hemagglutination assay (TPHA).Methods Research group included 3957 clinically asymptomatic syphilis patients,and control group was 344 outpatients with sex-transmitted diseases (STD).The serum samples from the patients who were TPHA-positive were tested in parallel by enzymeimmunoassay (EIA) and syphilis toluidine red untreated serum test (TRUST).Western blot (WB) was performed as confirmatory test.Results In the clinically asymptomatic patients,60 were TPHA-positive.Among them 57 were confirmed by western blot assay,and 1 was false-positive and 2 were borderline in WB.Of the 60 TPHA-positive patients,53 were positive in EIA and 23 were positive in TRUST.In STD patients 40 were TPHA,WB and EIA-positive but 32 were TRUST-positive.Conclusions The results of TPHA and EIA were consistent for diagnosis of syphilis patients who may suffer from previous or latent infection.