The problem of old urban district regeneration has to be solved in process of ur-ban development.According to the practice of urban construction and the current situation of urbandevelopment in our country,solving this problem is very urgent. At present.there is fewer discussionon old urban district regeneration from its economic and social effect; In this paper.by means of an-alyzing old urban district regeneration and its investment effect, a set of criteria evaluating the in-vestment effect of old urban district regeneration is eastablished. For the first tirne, a new method. Set Statistics-AHP (The Analytic Hierarchy Process)-Entropy method is adopted to evaluate the in-vestment effect,and successfully solve two critical problems,individual criterion evaluation and crit-era' s weight.