China began to strictly implement the “One Child” national policy of family planning in the early 1980s, and the “Two Children” policy was fully implemented since January 1st 2016. Here, why did China have experienced a serious gender imbalance under “one child policy” during more than 30 years? And what is the role played by high gender ratio in economic growth? This article analyzed the transfer mechanism of the Confucian culture to the sex ratio and we used the actual experience data to set empirical test. It is found that the “boy preference” phenomenon in the Confucian culture has increased the sex ratio, and the sex ratio has a significant positive effect on the economic growth rate.