The purpose of this study is to provide basic materials for improvement of unbalanced diet and nutrition habits of young children by investigating the general tendency and patent`s understanding of unbalanced diet of young children and finding out the effect of cooking activities on the unbalanced diet and nutrition habits of young children. Based on above purpose, the following research subjects were set; 1. How is the general tendency about unbalanced diet and nutrition habits of young children? 2. Will the cooking activities have an effect on the unbalanced diet to food of young children? 3. Will the cooking activities have an effect on the behavior of unbalanced diet of young children? 4. Will the cooking activities have an effect on the nutrition habits of young children? The results of this study were as follows; First, the result of investigating a general tendency about unbalanced diet of young children showed that the first was beans, and then comes vegetables, Kim-chi, cereals, and potato in that order. Second, The most serious nutrition habits was unbalanced diet. Third, The result of analyzing the effect of cooking activities on the unbalanced diet to food of young children showed that unbalanced diet decreased in 9 kinds of food ; vegetables, beans, Kim-chi, milk or sugar, potato, cereals, milk product, meat, and fruit except fish. Fourth, The result of analyzing the effect of cooking activities on the behavior of unbalanced diet of young children showed that 9 kinds of negative unbalanced diet decreased Fifth, The result of analyzing the effect of cooking activities on the nutrition habits of young children showed that 6 kinds of nutrition habits changed positively