The purpose of this study is to find the structural relationships among major satisfaction, career search efficacy, and career exploration behavior with marine science high school students. For investigating this topic, 524 students were surveyed from the marine science high schools. In order to find out the structural relationships among major satisfaction, career search efficacy, and career exploration behavior, structural equation modeling was used. Followings were the results of the research: (a) Major satisfaction effected significantly on the career search efficacy. (b) Career search efficacy effected significantly on the career exploration behavior. (C) There was not significant direct cause and effects from major satisfaction to career exploration behavior, but indirect effect was significant. Some recommendations were suggested for increasing career exploration behavior of marine science high school students.