Abstract: Objective To explore the related factors of gender of birth population in Tongliao city,Inner Mongolia.Methods We used cluster sampling method to sample the subjects from city,town and village,respectively.A total of 3 051 children who were born between Jan 1st,2006 to Nov 30st,2008 and their parents were investigated.A cross-sectional questionnaire survey was conducted to collect data with face-to-face interview.Results The concept of children bearing showed difference between the boy group and the girl group(P<0.001).Fathers and mothers of the boy group had the concept of boy preference with the percentages of 28.7% and 19.2%,respectively.The percentages of boy preference for fathers and mothers of the girl group were 14.4% and 22.8%,respectively.The concept of children bearing was different between the residents of city,town and village(P<0.001).Fathers and mothers in town and village were more prone to have a boy.The proportion of concept of boy preference in fathers of rural,town,and city was 28.0%,12.8% and 9.6%,respectively.The proportion of concept of boy preference in mothers of the rural,town,and city was 28.9%,30.8%,and 17.5%,resopectively.The results of logistic regression showed that the concept of boy preference in father was related to birth of boy (odds ratioOR=1.21),and concept of boy preference in mother was also related to birth of boy(OR=1.28).Conclusion The concept of boy preference in father and mother is related with birth of boy in Tongliao city,Inner Mongolia.