本研究從認知評估及誘發事件發生的頻率與強度兩項因素，建構少年縱火行為形成的理論模型。此一模型指出，少年之所以選擇縱火行為做為犯罪手段，是因為他／她對縱火有了正向評估，而少年對縱火的正向評估，則受到過去接觸火及觀察縱火經驗的影響。此外，誘發事件發生的頻率與強度，在少年對縱火具有正向評估及實施縱火行為之間，扮演調節變項的角色；這類事件發生的頻率高低或強度強弱，會影響對縱火具有正向評估的少年做出縱火行為的可能性高低。本研究以自陳式問卷進行資料蒐集，參與者為國中與高中學生693位，以及少年輔育院與矯正學校的犯罪少年688位，共計1,381位。問卷包含自編的少年對縱火的正向評估、接觸火的經驗、觀察學習縱火的經驗、各項誘發事件發生的頻率與強度，以及縱火行為等測量工具。研究結果顯示，少年親身接觸火及觀察縱火的經驗對其形成縱火的正向評估有直接影響，對縱火的正向評估對少年縱火行為也有直接影響，誘發事件發生的頻率與強度是對縱火的正向評估與少年縱火行為間的調節變項，上述結果皆符合理論模型的預測。文末就少年縱火行為形成的理論模型的意涵，研究結果的實務應用及未來研究方向加以討論。

In this study, we constructed a theoretical model of the causes of juvenile fire-setting based on cognitive appraisal and the frequency and strength of trigger events. We suggested that juveniles choose fire-setting as means to commit crime because they view fire-setting positively. The development of a positive fire-setting appraisal is influenced by experiences of contact with fire and observational learning of fire-setting. In addition, the frequency and strength of trigger events moderate the association between appraising fire-setting positively and the practice of setting fires. The frequency and strength of trigger events influence whether juveniles who appraise fire-setting positively are likely to set fires. This study used an anonymous, self-reporting questionnaire to conduct a survey and collect data. Participants included 693 junior and senior high school students from the northern, middle, southern, and eastern Taiwan, and 688 delinquent juveniles from every reform school in Taiwan. In total 1,381 juveniles were involved in the study. The questionnaire included scales developed for this study measuring the positive appraisal of fire-setting, the experiences of contact with fire, observational learning of fire-setting, the frequency and strength of trigger events of fire-setting, and fire-setting behavior. The results showed that experiencing contact with fire and observational learning of fire-setting directly cause juveniles to appraise fire-setting positively, that the positive appraisal of fire-setting directly affects juvenile fire-setting, and that the frequency and strength of trigger events influence the association between the positive appraisal and the practice of juvenile fire-setting. The predictions of the theoretical model were supported. Finally, we addressed the implications of the theoretical model, the practical applications of the results, and the potentials for future study.