Secondary schools in Korea have been faced with several critical problems in their science education. Among them the most fundamental are the problems which involve the development and operation of science curricula. This study had, therefore, its objective to develop the suggestions for sabstantial science curricula of secondary schools. Actually the objectives are trifold as following specific description. ${circ}$Analysis of the rationale and theory of science curricula. ${circ}$Status survey of secondary science curricula and identification of the problems in development and operation of the curriculum in foreign and Korean secondary schools. ${circ}$Development of suggestions for substantial science curriculam of secondary school. In order to attain these objectives the methods of literauare survey. questionaire and interview were used. Through these methods several problems are found and identified. The major findings and problems identified in this study are: ${circ}$aims, goals, and objectives of science education are not dfferentiated. ${circ}$the curricula show discipline-centered seleetion and organization of the content:neglect the relationship of science-technology-society and life-world context. ${circ}$shortage of weekly instructional hours for science subjects. Other findings and problems are described and the descriptions of the suggestions for substantial curricula are followed at the end of this paper.