This study was conducted to explore the effect power of ego-state by analyzing the effect size of ego-state related variables and moderating variables of adolescents. To this purpose, total 23 journals which published recent 20 years meta analyzed. 600 ego-state related variables extracted from total 23 studies classified into positive, negative, individual trait, family trait, and school trait. According to analysis, all the total effect size were disparate and mid level effect size. Positive variables appeared A, NP, AC, FC, CP and negative variables showed AC, FC, NP, A, CP in turn. The effect size of positive ego-state related variables showed individual trait, school trait, family trait, and the negative ego-state related variables appeared family trait, school trait in turn. Through these results, it has been confirmed that the ego-state of teenagers develops in a balanced manner when variables such as stroke, life-position, parenting, and school adaptation act positively. Based on the results, limitations of study, implications on counseling, etc were discussed.