Recently, endocnne dIsruptors have been known as one of the most harrnful chemical material. The purpose of this study is to investigate the cogintion and behavoor of milddle school students on the endocrine disruptors. To achieve this goal, survey research was conducted. Data were collected from 531 first and third-grade students in Suwon city. The main results of this study are summarized as follows FIrst, the mam source of information on the endocrine disruptors was mass media such as TV. This means environmental education in school is needed and mass media can be a very important tool for education. Secondly, as grades become higher, more students had knowledge on the endocrine disruptors. The difference between boys and girls was not significant. Thirdly, most students recognized endocrine disruptors as a dangerous material. However, they had an optimistic view on the possibility of resolving the environmental problems using science and technology in the future. Lastly, the scores of environmentally sound behavior was not highly correlated to those of knowledge. This means that in current environmental education system, more knowledge on the endocrine disruptors do not ensure more environmentally-correct behavior. These survey results show that environmental education on the endocrine disruptors should be constructed to induce correct behavior. That is, environmental education from now on has to be conducted to change the behavior of student as well as to increase knowledge.