The performance of incubation policy should consider both incentive effect for providing innovation service and service supporting effect for incubating enterprises’ growth. This paper put forward a multi-level conducted evaluation framework for incubator policy. Based on the survey data between 2008 and 2012 on implementation of the incubator preferential tax policy, it empirically investigates the integrated effect of incubator preferential tax policyby three stages of simultaneous equations model. The result indicates that there are regional differences in the implementation of incubator’stax preferential policy. The policy effectively incentivized the basic service like accommodation and technical personnel, but it didn’t have significantly positive effect onfinancing andsocial networks. Actually, the latter is a moreimportant factorfor the innovationperformance of incubating enterprises. It highlights that the future policy emphasis of incubator should be turned from basic services to innovation services, such as financing, social network, entrepreneurship mentor, etc.