The main purpose of this study was to examine the effect of emotion development program on young children’s problem behavior. The subjects of this study were a total of 60 young children, among which 27 children were 4- year- olds and 33 children were 5-year-olds who were all enrolled in kindergarten and child center located in the city of Ulsan. The design of this study was experimental study. Thus, 20 young children were placed in experiment group and 40 young children were placed in control group. Young children participated in both pretest and posttest. There was statistically significant difference (t=2.58,p<.05)in total score of K-CBCL among young children in either experimental group or control group. There was significant decrease in behavior problem score of young children who conducted emotion development program compared with young children who did not conduct emotion development program between pretest data and posttest data. Thus, emotion development program positively affect young children’s behavior problem decrease.