The Youth at Risk Ministry Office of the Catholic Diocese of Hsinchu, which is based on the value of the Gospel, cultivates deeply into the lives of the youth at risk. The approach is different from the strict social work doctrine of managerialism, standard procedure or cost-benefit performance. It uses the whole person's caring approach and long term involvement to accompany psychologically traumatized youth at risk, with the hope that when juveniles receive the "care" a transcendent energy will naturally entrust them with the power to sprout inner goodness as well as the understanding of what is good. This research used quantitative methods to explore the intervention effectiveness of the agency toward these youth at risk. Based on the research and practical experience, the deviant behaviors of the youth at risk probably in the areas of 1. problematic behaviors, 2. psychological health problems, and 3. alcohol intake, smoking, chewing betel nut and drug abuse. We used the measurement tools of the Behavior Checklist, TSCC-A Booklet and combined the questionnaires of the American Drug and Alcohol Survey and the Taiwanese Healthy Behavior Survey to measure the behavior scores of these youth. We selected 60 sample of those youth who entered the agency in 2013, gave a pretest at 2015 and gave a posttest at 2017. We used the experimental design to compare whether there was a significant difference between the scores of pretest and posttest. We also compared the statistics of the deviant behaviors of the youth in the agency in the past(2009-2015) and present(2017) (please see the appendix 2). The results of the experimental design were as follows: 1. In the behavior checklist, the results showed many improvements of the youth in the areas of emotional self- control and interpersonal interaction. 2. In the drug use scale, the result showed that the Ketamine use had been under control. 3. In the trauma scale, the results indicated that there were some improvements in the youth's emotional control and psychological security. In conclusion, it is proven that the intervention method of the Youth at Risk Ministry Office is effective in general.