CMIP, the Coupled Model Intercomparison Project, established under the auspices of World Climate Research Program (WCRP) includes a series of intercomparison projects for global coupled ocean-atmosphere general circulation models. Its purposes are to evaluate and develop climate models by intercomparison, and to provide reliable scientific basis for ecology, hydrology, social economics to estimate future environmental changes in the various global context as well. CMIP was developed from AMIP in 1995, and experienced three steps with CMIP1, CMIP2 and CMIP3, which has provided the longest so far and the most extensive database for model research. Although the results of the simulation model still included some inevitable uncertainty, countries around the world have applied this database to develop models and research multi-disciplinary associated with climate changes, which has provided an exclusive scientific basis for the forecast of future climate changes. This paper reviewed the project and discussed the present problems and the potential prospects of using this project in China briefly.