Since 1980's,with the implementation of opening and reforming policies,a large amount of investment from home and overseas has been introduced to China's opening cities. Therefore, the study of urban investment environment is very importnt.This paper focuses on the investment environment assessment which is indispensable in the study of investment environment,and puts forward the methods of assessment.Methods of determination of assessment area, quantification of assessment unit,selection and quantification of assessment index which are different from previous agricultural land assessment and urban land price classification have been mentioned,On the basis of above analysis,two investment environrnent assessment models of Expert Scoring model and Fuzzy Assessment model have been designed.Their integrated model has been successfully applied in the comprehensivequality assessment of investment environment and suitability assessment for various enterprises in the city of Ningbo.