Abstract: How to increase the adequacy and elevate overall planning level of pension system impede the reform process. By reflecting the dynamic process between the central government, local governments and firms, institutional origin in pension reforms is revealed, public choice theory and evolutionary game theory are combined, the integrated level of pension system is defined, and a promoted Predator-Prey Model is used to study how the pension reform in China (increasing the integrated level of pension system) can influence the relationship between central government, local governments and technology firms. It's suggested that increasing the integrated level of basic pension system, reacting positively to aging population, encouraging retirement income diversity and improving management efficiency of the pension system could not only promote a successfully pension reform, but also boost the economy growth. While over-integrated and fast speed of integrating will exceed the capacity of market, thus to lose the efficiency of the policy.

Key words: integrated level, evolutionary game, basic pensions, experiment