The purpose of this study is to develop vocational English textbooks for vocational high school, especially marine production high school. Vocational English is intended to increase English proficiency in the area of specific industry or jobs. Based on the review of the literature, the study established developed vocational English textbooks for marine production high school based on the modular system. The developing process includes analysis for marine production job, marine production high school and current English textbook for marine production. Based on the analysis, this study developed English contents which marine production students utilize in not only school but also workplace. Also, this study suggests future research directions for effective development and use of the textbooks in the vocational high schools.