Abstract: This article starts with an introduction to the various functional relations of the parameters formulated by the utility maximum model and the expense minimum model, and then discusses the relations of the three variations--EV (the equal variation), CV (the complementary variation) and AV (the indirect efficiency variation)|the third step is to define and formulate U (q,p,m), the efficiency function of the currency measurement, and last step is to explain that EV and CV can replace CV for measuring the variation of the consumer's welfare and further analyzes the relations between EV,CV and CS (consumer's surplusage).