Objective To explore the impact of the women taking warfarin throughout pregnancy after mechanical valve replacement on the children’s physical and mental development.Methods A total of 12 children whose mothers had taken mechanical valve replacement before pregnancy were enrolled in the experimental group in this study, for determination of their physical and mental development. The following indicators were measured: a) Physical development indexes: height, weight, sitting height, head circumference, chest circumference; b) Mental development indexes: intelligence quotient (IQ), and development quotient (DQ) which included adaptability, big movement, fine motor, language, and individual-society. According to the 1?∶?2 matching ratio, 24 children of the healthy women were selected in the control group, and then the difference of each index between the two groups was analyzed. Results In the aspects of both physical development indexes and mental development indexes, there were no significant differences in the children aged 0 to 3 yrs, 4 to 6 yrs, and 6 to 12 yrs in the two groups (Pgt;0.05). Conclusion After mechanical valve replacement, women taking oral anticoagulant warfarin in daily dose not exceeding 5mg are safe, and there are no negative effects on children’s physical and mental development.