Abstract: Objective To investigate syphilis infection status among partners of married syphilis-infected pregnant women, and analyze the associated factors from the perspective of both pregnant women and their partners. Methods Follow-up survey and contact tracing were conducted among married syphilis-infected pregnant women diagnosed from 2008 to 2011. Both toludine red unheated serum test (TRUST) and treponema pallidum particle agglutination (TPPA) were applied to partners attending antenatal care clinics. Structural questionnaires were used to collect information. Binary logistic regression model was applied to analyze the factors associated with partners' syphilis infection. Results Totally 2 261 pairs of married syphilis-infected pregnant women and their partners were recruited. Based on laboratory record, 528 partners were with positive results for both TRUST and TPPA (23.35%), and 129 partners were with positive results for only TPPA (5.71%), thus syphilis infection rate among partners were 29.06% (657/2 261). The partners were more likely to have syphilis infection when pregnant women were with TRUST titers ≥1:8, were with diagnosis of early syphilis or had received adequate treatment before pregnancy (all P<0.05). The partners had higher risk of syphilis infection when they had lower education level, or had multiple sex partners (all P<0.05). Conclusions Syphilis infection rate among partners of married syphilis-infected pregnant women is high. Pregnant women's levels of TRUST titer and disease stage as well as partners' sexual behaviors were important factors associated with partners' syphilis infection.