Syphilis serological tests include non-syphilis spirochete antigen serological tests (commonly indicated by RPR) and syphilis spirochete antigen serological tests (commonly indicated by TPHA, TPPA, etc.). (A) RPR 1, as a routine test or screening in a large number of people, such as census, marriage, prenatal and other health examinations, etc. 2.It can be used as a quantitative test to observe the efficacy, whether recurrence or reinfection. 3.Identify early and late latent syphilis, the titer of the former drops quickly after treatment, the titer of the latter drops slowly or remains unchanged. 4.Differentiate congenital syphilis from passive reactive toxemia. 5.Cerebrospinal fluid for VDRL test, help the diagnosis of neurosyphilis. (B) TPHA/TPPA 1.The test has high sensitivity and specificity, and is generally used as a confirmatory test. 2.The test detects anti-syphilis spirochete IgG antibody, even if the patient is treated with sufficient anti-syphilis therapy, the serum reaction remains positive, so it is not used to observe the efficacy, recurrence and reinfection.