The purposes of the study were (1) to examine the effects of a youth network on vulnerable youths' social adaptation knowledge, (2) to examine the vulnerable youths' satisfaction with the youth network on social adaptation development, and (3) to examine the effects of a youth network on vulnerable youths' changes in behaviors of social adaptation. The participants consisted of 302 vulnerable youths in the northern Thai province of Khon Kaen selected by a systematic sampling method. A group of 10 authorities was also chosen purposively to join the interview session. The instruments included a youth network plan, a social adaptation test, and an interview form. Frequency, percentage, mean score, S.D, and t-test were used to examine the data. The content analysis assessed qualitative data. The findings study reveals how a planned youth network resulted in the acquisition of knowledge, attitudes, and desirable behavior among youngsters at risk.