The purpose of this study was to develop an instrument to check daily living skills for chronic mentally ill, to analyze the effectiveness of a community-based mental health program on the improvement of daily living skills for the chronic mentally ill, to find out the difference of their daily living skill levels according to the duration of their participation in the community-based mental health program. The research design was a form of single group pre-post experimental design. The subjects for this study were 26 chronic mentally ill who lived with their family members in the community, and participated in community-based mental health program of Sonbuk Health Promoting Center. The data were gathered from August 1, 1996 to August 31, 1997, and analyzed suing paired t-test and one way ANOVA with SPSS pc. The results of this study were as follows : Main hypothesis : The hypothesis, "there will be a difference in the scores of daily living skills of chronic mentally ill according to the duration of their participation in the community-based mental health program", was supported(the mean at 0 month : 2.66, the mean after 6 months : 2.93, the mean after 12 months : 3.18, F=3.29, p=.0425). Subhypothesis 1 : The subhypotesis, "there will be a difference in the scores of before(0 month) and after(6 months) participating in the community-based mental health program", was supported(the mean at 0 month : 2.66, the mean after 6 months : 2.93, t=-3.15, p=0.004). After the participation in program, the chronic mentally ill get higher scores of their daily living skills than before the participation in the program. Subhypothesis 2 : The subhypothesis, "there will be a difference in the scores of after 6 months and 12 months after the participation in the program", was supported(the mean after 6 months : 2.93, the mean after 12 months : 3.18, t=-2.41, p=.023). Subhypothesis 3 : The subhypothesis, "there will be a difference in the scores of before(0 month) and after 12 months participation in the program", was supported (the mean at 0 month : 2.66, the mean after 12 months : 3.18, t=-4.14, p=.000). After the participation in the program, the chronic mentally ill get higer scores of their daily living skills than before the participation the program. The people who participated in the community-based mental health program for a longer period, showed the more improvement in their daily living skills.