This paper analyzes the causes of Xinning transformation, and compares the transformation of Xining and Yuanfeng, and then points out that although the new law is not abolished untill the period of Yuanyou, the Xinning transformation should only refer to the period of Xining. Shenzong's imperial power is believed to be the main reason for the failure of the transformation and the author finally put forward two sugustions for people to learn today.