A comparative analysis on Environmental Impact Assessment of urban planning and Implementation Evaluation of urban planning

City is a complex dynamic and open artificial ecosystem, also the urban planning object of study and practice. It's especially important that the evaluation of urban planning because it has made great impact on environment society and economy. Environmental Impact Assessment (EIA) of urban planning and Implementation Evaluation (IE) of urban planning fall into the same category of evaluation research while are different in some ways. Comparatively analyze EIA of urban planning and IE of urban planning from an angle of system theory, including purpose, object and subject, intervention period and evaluation method five parts. At last give some advices on the field of evaluation of urban planning at present China.