This paper aims to review the environmental education theories in the curriculum of the teacher education program and to investigate the effect of the instructional module on Environmental Ethics.After 12 hours of instructional module, the researcher distributed every pre-service student a disk which was imbedded with ten open-ended questions for the learners to answer their opinions on. The data showed that the learning process was very smooth and the learners' achievement was satisfactory, especially in flexibility and diversity of learning activities, invoking their reasoning and critical thinking. The drawbacks were the difficulty of controlling the instructional time, the lack of practices, and the isolation from local environmental personnel.