The number of traffic accidents has been increasing in the recent years in Japan, while the number on other advanced countries trends decreasing. The effective policies for traffic safely had been conducted in1970's and there are no ideas which can decrease the number of traffic accidents in a short term. Therefore, from a viewpoint in along term, new infrastructure planning for traffic safety is required. In this paper, the relations between road structure and traffic accident are studied. A Geographic In formation System(GIS)is built for the analysis of traffic accident which is caused by many factors. First, it is shown that the visualization by the GIS is effective for accident analysis. Second, several multi-variate analyses with the data processed from the GIS are examined and the factors of accidents are specified. Finally, the required additional data and analysis methods for further research are discussed.