When the enterprise carries on project investment, it should carefully make full use of various investment decision methods to evaluate them, take or reject and finally choose the best, in order to escape the blindness of investment. And the estimation of economic effects as the core material of estimating various investment projects’ economic effects,is used in the vast realm, even plays the important function especially for the enterprises’s investment. But both the constitution of the current economic effects index system and the application of the estimation methods exist some unreasonable aspects. Recognizing these existent problems and looking for the better ways to resolve them doubtlessly have much more important realistic meaning towards raising accuracy and sciences of economic estimation.In order to maintain the scientific correctness of an investment decision ,it is important to establish a rational index system for estimating economic effects and to correctly use estimation methods. This text is divided into three parts and combines the relevant actual examples to analyze the current economic effects evaluation index .It points out the problems of the existing index system and the estimation methods and carrys on the comparison to the existing indexs then combines the authority organization to analyze actual applied circumstance of these indexs. On the basement, the text improves the current system and methods and puts forward the new economic effects estimation indexs then analyzes the new constitution of the improved index system and estimation methods.
Keywords: investment decision;economic effects estimation;index system;estimation methods;improvement