the sixth national population census data of Ningbo City, analysis status of birth population sex ratio imbalance in Ningbo City, based on the cultural, social, policy and technical perspective analysis of the source of the birth sex ratio imbalances, and advice from the promotion of gender equality and the care women"s social atmosphere, government policies and laws and regulations should pay attention to "gender", timely steadily relaxed child birth policy, to carry out the comprehensive management of the imbalance of sex ratio at birth of local legislation, , in order to solve the problem of the birth sex ratio imbalance.