Japan's Environmental Impact Assessment Law was enacted in 1997. However, there are still many problems in Japan's ecological impact assessments. Among these problems, we turned our attention to problems stemming from 1. The system of Japan's EIA ; 2. The team of EIAs ; and 3. Technical methodologies. We applied the Habitat Evaluation Procedure for the first time to an EIA in Japan. Through this experience, we reviewed effectiveness of HEP as a solution to the above problems in Japan's EIAs. The proposed project was a residential development in Yokohama. The site was located in one of the largest remaining natural suburban areas in the city,consisting of densely vegetated hills and creeks which provide quality habitats to wildlife including fireflies and brown frogs, selected as evaluation species in this HEP. Some modifications of original HEP were introduced, including technical revision for the fragmented natural area which has a peculiar land use in Japan. As a result, HEP contributed to formation of substantial mitigation measures for habitats conservation through analyses and discussions among HEP team members.
