The paper focuses on 1980-2000 Mainland China religion policy change and influence. I adapt field study method-depth interview-to collect raw data. I have interviewed three kinds of elites, including Mainland China religion administration bureaucracy elites, religion group's elites and religion researcher elites. Comparative these elites opinions, try to understand following questions: 1. Does Marxism ideology causes Mainland China religion policy change? 2. Does Mainland China religion policy change influence five major religions developing? 3. Does Mainland China religion policy change limit the new religious group and foreign religious group developing? 4. How to interact between legal religious group and illegal religious group with Mainland China administration bureaucracy?