本研究旨在探討親子遊戲治療對於外化問題兒童與母親親職壓力之成效。對象為「兒童行為檢核表」外化量尺T 分數達邊緣臨床範圍以上（T ≥ 60 分）之六對兒童及其母親，對其進行為期十週、每週一次2 小時之親子遊戲治療。本研究成效之評估採質量並呈方式，量化部分採單組前後測設計，團體開始前和結束後實施「兒童行為檢核表」和「親職壓力量表」前測、後測和追蹤測，以及「教師報告表」之前測、後測，進行Wilcoxon 符號等級考驗；質性部分，在團體結束後對六位母親進行約1 小時之個別訪談，以探究外化問題兒童母親參與親子遊戲治療團體的經驗。研究結果：1. 親子遊戲治療對外化問題兒童之內化、外化問題與整體問題，以及母親親職壓力具立即與持續改善效果；2. 質性分析顯示，外化問題兒童母親之成效包括：覺察與理解、正向改變與看見美好、家人關係與溝通的改善等面向。綜合上述結果發現，親子遊戲治療對研究對象具有正向之影響。根據研究發現提出建議，以供實務工作及未來相關研究之參考。

This study investigated the effects of filial therapy on children with externalizing behaviors and mothers’ parenting stress. The results obtained using the Achenbach System of Empirically Based Assessment show that six parent-child pairs among the members had an externalized scale t score above the marginal clinical range (t ≥ 60). Based on the study design, the members were invited to participate in a filial therapy group for 2 hours per week over the course of 10 weeks. The study was also conducted over the course of 10 weeks. The study adapted both quantitative and qualitative research methods; the quantitative method uses a single-subject design. The members were administered the pre- and pro-tests of the Achenbach System of Empirically Based Assessment and the Parenting Stress Index, as well as the Teacher’s Report. After the test, the Wilcoxon signed-rank test was used to determine the results. For the qualitative method, to investigate the experiences of mothers who had children with externalizing behaviors in the filial therapy session, the members were interviewed individually to explore the experiences of mothers for 1 hour after the session was completed. This study provides the following research findings: (1) Filial therapy had significant effects in terms of not only reducing the children’s problems related to internalizing, externalizing, and overall parts but also in rapidly reducing the mothers’ parental stress continuously. (2) The qualitative data analyses showed that the effects of the filial therapy program on the mothers of children with externalizing behaviors include awareness and understanding, positive changes, finding wonderful things in life, and improving both family relationships and communication. The study results show that filial therapy had positive effects on all the members, including by reducing children’s externalizing behaviors and reducing mothers’ parental stress. This study not only proposes relevant recommendations based on the research findings but also provides viable suggestions for future research.