This qualitative study examines the effectiveness of intervention strategies for helping children with internalizing problems based on the successful experiences of nine school counselors. Interventions can be divided into three phases. The key success factors at each phase of the intervention are as follows. At the first stage, adopting an observing and going along attitude, using art and game media to promote client expression and establish security and rapport. At the second stage, incorporating language therapy in the intervention to discover client strengths and characteristics, through encouragement and praise, creating safe attachment, individualization, and self-awareness of positive experiences. The third stage is the design of the peer-play plan. The key success factors are: satisfying interpersonal needs, improving self-efficacy, boosting self-confidence in positive thinking, and transferring back to the class system to enhance adaptation.