The purpose of this study was to provide informations on what middle school students know and think about food additives, and their purchase behavior of processed foods containing food additives. The data were gathered by questionaries from 360 students attending in the 3 randomly selected middle schools around Gyeonggi Province. The valid 340 out of 360 questionaries were analysed by SPSS/WIN 12.0. As a result, the middle school students showed low interest in 4 kinds of representative food additives such as synthetic seasoning, artificial sweetener, artificial dye, and synthetic preservative. They thought that the food additives is necessary but not improve the quality of food, and may have harmful effects on health. The students who has mother of university graduate, and taught by text book A showed the highest interest. Most students rarely checked the indication of food additives on the processed food package, and they hardly put any effort to avoid the processed foods containing food additives. According to the results of this study, the students were not aware and did not know about the food additives enough, and needs to be educated more and in detail in home economics class.