Objective:To explore the fluctuant trend of sex ratio of newly-born population in Jiangsu Province. Methods:The population sex ratio was obtained by the government’s official web site and Jiangsu family planning commission. Results:The birth sex ratio of Jiangsu Province was high. There were differences among 13 cities, as well as between urban and rural areas. Birth control policy also affected birth sex ratio. Conclusion:High birth sex ratio does great damages to building a solid family and keeping family friendly and stable. It is also disadvantageous to the peace and harmony of society and harmful to maintaining the low fertility level.