As a sense of practical field, most researchers emphasize the importance of safety management to prevent marine accidents. The purpose of this paper is to develope a new safety evaluation method using Safety Index (SI) which is to measure the emotional feeling of navigation officer by traffic situations. In this study, the questionnaires with SI are used to investigate the degree of sensing levels of navigation officers according to the navigation situations. In addition, the traffic data obtained from AIS (Automatic Identification System) data are used to give actual situations in the questionnaire investigation. As results of questionaries investigations based upon the AIS data, it is shown that the Safety Index can be used as a criterion to determine the safety levels of ship navigating in a coastal areas.