Since Environmental Education in Elementary School is taught separately in various subject area, a well-founded and organized curriculum in integrated Environmental Education is needed to educate teachers for professional development. In this research, a curriculum for elementary teacher in-service training program was developed in order to improve both environmental and educational competencies of elementary school teachers. The curriculum was based on the needs analysis on Environmental Education training for elementary school teachers. Also it was based on international and updated perspectives on Environmental Education, Education for Sustainable Development. The curriculum consists of the introduction and the particular perspectives. The particular is made of 60 hours, which covers 6 perspectives on environment. They are ecological perspective, environmental ethics perspective, social-cultural perspective, economic perspective, environmental hygienic perspective, and environmental policy. Environmental policies of Korea and the world were included so that teachers will understand efforts made at national level and participate more to environmental action in their schools. Lesson objectives were specified for teachers to apply this curriculum to their classroom easily. Related elementary curriculum and textbook were indicated at the end of each lesson so teachers can link their training setting with their classroom setting. Especially, in this curriculum various teaching and teaming methods for each lesson are introduced. Thus, this re- search is very practical for elementary school teachers who are planning to teach environment in their classroom.