Abstract: After victory of the new democracy revolution, it should take a long time to construct new democracy. Only if material and mental conditions become in full maturity, the transition from the new democracy to the socialism may be realized in China. These were the original conceptions made by Mao Zedong and the Central Committee of the Communist Party of China before or after the founding of China. However, with the completion of national economic recovery, they had developed some novel thoughts and ideas about the transition to socialism, and then put forward the thoughts of the general line for the period of transition. From above, it can be seen that the Central Committee of the Communist Party of China experienced tough exploration on the problem of transition from the new democracy to the socialism so as to change greatly in its cognition. In general, the general line for the period of transition is not only the objective requirement to develop quickly national economy, to enlarge plan economy, and to implement smoothly the First Five Plan, but also the necessary consequences of utilizing industry and commerce of capitalism and confining their development. At the same time, it's the consequent trend for the development of rural economy after land reform, and also the orerequisite for consolidating people's dictatorship.