Abstract: Objective: To explore the clinical significance of Treponema pallidum-enzyme linked immunosorbent assay(TP-ELISA),syphilis toluidine red untreated serum test(TRUST) and treponemapallidum particle agglutination assay(TPPA) in the diagnosis of syphilis.Methods: The syphilis in the clinical samples were screened by TP-ELISA,and the 93 positive specimens and 16 specimens with the 0.80 to 0.99 of S/CO value were further confirmed by TRUST and TPPA.Results: Among the 93 positive specimens,83 positive cases and 6 weakly positive were identified by TPPA,the positive coincidence rate of which was 95.70%(89/93).Among 93 positive syphilis cases detected by TP-ELISA,the 32 TRUST positive cases were confirmed,and which was positive by the TPPA detection too.Among the 61 weakly positive samples detected by TRUST,the 51 positive cases,6 weakly positive cases and 4 negative cases were identified by TPPA.Among 16 cases with the 0.80 to 0.99 of S/CO value,the 1 positive case and 1 weakly positive case were identified by TPPA.Conclusions: The syphilis screened by TP-ELISA exists false positive and false negative.The TRUST should be tested in TP-ELISA positive specimens at first,and the TPPA in negative TRUST specimen should be further detected to identify.The TPPA in specimens with the 0.80 to 0.99 of S/CO value should be further detected to decrease the misdiagnosis and missed diagnosis rates of syphilis.