Abstract: According to the characteristics of “gray” in human thinking,this research raised the clustering evaluation model of FDI comprehensive welfare effects based on the relative indicators．It determines the clustering indicators,ra-ting standards and clustering grays in terms of data collected and on the basis of gray system theory．Then,through establishing whitenization weight functions to carry out gray clustering analysis,it can not only distinguish the categories of welfare effect,but also demonstrate the affiliation levels of each sample on various categories in the gray clustering coefficient matrix．At last,it makes a clustering evaluation and analysis on the FDI comprehensive welfare effect ranging from 1986to 2008and the conclusion is highly reliable and relevant．

Key words: Whitenization weight functions,Foreign direct investment,Comprehensive welfare effect,Immiserizing growth,Gray clustering