This study investigated elementary school students` conceptual understanding of the greenhouseeffect. Data collected from 293 elementary school students, who were 6 graders of elementaryschools in the National Capital region, and Gyeongsang region. Considerable number of them definedthe greenhouse effect as the temperature increase in the globe, namely, the global warming ratherthan the exact description of interactive meaning of maintaining the high temperature of the globewhich is the consequential result from the greenhouse gases, the cause of greenhouse effect. Andit was surveyed that the misconception was formed because the terminology of greenhouse effecthas been used in analogy to explain the natural phenomenon in easy way. And both of the boyand girl students recognized that the global warming was the major reason of the greenhouse effect,and more preferred understanding was the negative influence than the positive influence on theglobal environment. Therefore, the development of teaching materials are important to form thecorrect environmental or scientific concepts to the students.