Propelled by economic globalization, regional economic communication has been gradually prevailing. The regional flow of productive elements, with capital flow as one of the primary forms, certainly advances the development of investment. Whether the investment will be well promoted lies in whether an attractive investment environment has been built up, as well as its competitiveness compared with other regions. The thesis firstly establishes concept structure and index system of competitiveness of regional investment environment, and then applies AHP model and yaahp 0.4.1 AHP analysis software to evaluate regional investment environments of seven provinces(including a municipality )，in hope of offering countermeasures and proposals to optimize regional investment environment and promote the competitiveness of regional investment environment.