The purpose of this study is to develop and verify the effectiveness of group counseling program, based on the Schema Therapy(ST) and the Acceptance-Commitment Therapy(ACT), for the growth of psychological professional trainees. For this purpose, psychological professional trainees(n=7) were surveyed, and research participants were selected. Based on program development model, this study conducted content validity verification, conducted a paired samples t-test, and calculated effect size (Cohen s d) to verify the effectiveness of the 18 session program. As a result, introspection (t=-2.04, df=6, p=.04), clarity of emotional recognition (t=-3.16, df=6, p=.01), and emotional stability (t=2.81, df=6, p=.01) showed statistically significant changes. Although acceptance (t=-1.34, df=60, p=.11) did not show a significant change, its effect size being middle level(d=-0.50) indicates that if the test is conducted in a larger sample, a statistically significant outcome could result. This study is meaningful in that it verified the effectiveness of a systematic expert training program that applies the ST and the ACT. Since the program’s effectiveness has been verified in this preliminary study, it is suggested that a controlled or longitudinal study should be conducted to re-verify the effectiveness of this program.