Abstract: This paper introduces the model of concordance analysis to evaluate the e-commerce websites and illustrates the model with an example. The concordance priority index and disconcordance priority index of the theory can be used to disclose the character of the evaluated object from degree of contentment and that of discontentment. Compared to other methods, this model includes the object’s advantages and disadvantages so the evaluation result is objective, creditable, easy to apply and program, above all, more informative than other methods.