Objective To investigate the status of folic acid(FA) supplementation and determinants of its use in pregnant Chinese women.Methods In this cross-sectional study,questionnaires were used to collect information of participants and FA supplementation.Women were recruited between 6 and 12 weeks postpartum in Tianjin,China,between July 2015 and July 2016.Results A total of 1,921 women were recruited in the study.Approximately 93.1% of the study participants used FA,while 14.4% of the women taking FA from three months prior to preconception to three months post-conception.Women who took FA for three months prior to preconception through at least three months into their pregnancy were more likely to be between 30 and 34 years old(OR=2.91,95% CI:1.15,7.33),employed(OR=2.07,95% CI:1.17,3.67),primigravida(OR=5.20,95% CI:3.02,8.96),married to spouses with an intermediate education level(OR=2.92,95% CI:1.45,5.89),and earn a high family income(OR=3.19,95% CI:1.57,6.49).Conclusion The prevalence of periconceptional FA intake was far below the requirements of the National Health and Family Planning Commission of China;therefore,knowledge of FA supplementation should be strengthened among women who are or planning to become pregnant.