The purposes of this study were: (1) evaluating the opinions of Korean professors, in departments of earth science education and departments of geology about the science concepts related to environmental issues that might be important for secondary, preservice earth science teachers in Korea, (2) ranking the environmental education topics to be included in a one-semester, sophomore-level, earth science courses for such teachers, and (3) designing environmental earth science lecture and laboratory course based on the topic rankings and educational theory. A researcher-developed opinionnaire contained 63 items relating to the 14 major environmental earth science topics found in suitable textbooks. The opinionnaire used a four-choice, Likert-type scale and was completed by 47 professors in summer, 1996: 17 from 10 earth science education departments and 30 from nine geology departments. These responses came from 51.1% of the sample population. At present, very few environment-oriented courses are offered in earth science, teacher education programs in Korea. Respondents considered the topics of "Waste Disposal" and "Fresh Water Resources and Pollution" as the most important to be included for prospective teachers. Other urgent environmental problems such as soil pollution by pesticides, air pollution caused by hydrocarbon fuels, landslides, flooding, typhoon, and droughts also were considered important. There was a high correlation (r =.87) in ranking of importance of topics by both groups of professors. This study shows that environmental earth science course should emphasize more on "the human impact on the environment" rather than "natural environmental hazards." On the other hand, natural hazards that commonly occur in Korea should be emphasized more than those that do not commonly occur in Korea. They also approved inclusion of some topics that had more relevance to non-Korean settings perhaps to make the course of greater worldwide relevance. Sample units of the proposed course are described for use in traditional- or constructivist-oriented approaches. By introducing the strengths of both constructivist and traditional teaching and learning, secondary school preservice teachers would experience various instructional strategies.