Objectives: The purpose of this study were to develop a family-based program for the parents of the high-risk adolescents to prevent youths from substance abuse and to explore the effects of the program on the knowledge, attitudes, and strategy of prevention, and the satisfaction to the program among the parents. Method: A quasi-experimental design was performed in this study, from 05/2004 to 06/2004, in which, eight high-risk students’ parents were included in the intervention group, while the other eight parents were in the control group in Taipei County. All of these adolescents of these parents were in the 7th grade and 8th grade. The intervention group received two-hour course in the drug abuse prevention program, while the control group received no intervention. Both groups received pre-post test before and after the drug abuse prevention program. Fisher exact test, Wilcoxon Mann-Whitney U test, and Wilcoxon Sign-Rank test were applied to describe socio-demographic data and to estimate the program effects on knowledge, attitude, and strategy of prevention among the parents by using SPSS 10.0 for Windows. Results: The main discoveries were as follows: 1. Most of the parents did not use any addictive substance, but one parent in the intervention group had used glues and amphetamine before. 2. These results accepted assumption 1 and 2, which indicated that there was significant between the intervention and control groups on knowledge, attitudes toward substance prevention. And these results rejected the assumption 3, which indicated that there was no significant difference between the intervention and control groups on strategy of prevention. However, the performances of knowledge, attitude, and strategy of prevention related to the prevention of substance abuse within the intervention group were better than that within the control group. 3. Most of the parents, who received the substance abuse program, demonstrated their likes to these activities. These activities were designed lectures and practices, which provided practical information regarding substance abuse prevention, and also led parents’ attention and interest to the program, parents demonstrated that two of these activities were very useful. These three activities were designed for parents to recognize substance abuse. Conclusions: Based on the results, the study suggests that the parental program designed for youth substance abuse prevention could be the basis of other family-based adolescent’s substance abuse prevention programs.