The main purpose of thesis research was to study the  community development on   the morality  of  the  youths  in  Khon kaen  municipality region 3, and impact of community development on the morality, applying the Buddha Dhamma to solving the youth problems. The result of study, was found that :-

                  There were four ways  of  developments in Theravada Buddhism, behavior, society, feeling and mind. But the community development in this thesis is laid by Buddhist economic. Thus community is organized  from two persons to help some activity to benefit them with philosophy in working. Besides, they must make their community strong and can depend on selves. Helping form outside by unless. The ways are for development their community, such as, visiting home of members, debate about activities, showing ctc. The problems and causes of youths were inside occurred from them, outside occurred from environment of city society, friends, and other factors such as, place of recreation, game zone, the malls which easy sells. Impact  of   community development were  to  the youths directly, for example, make them become value wrong to over have and maturity, impact to their family, such as, over spend, problem of them without warm, impact to community, such as, a little stealing, making trouble by riding fast for danger, making over voice, impact to school, such as, they do not respect to their teacher, often crass on study, contact with other school and do wrong by law.

                  Result of the community development to morality of  youths are activity of visiting, showing, exhibition, campaign no smoking and no drug, study and seeing work from other community, and activity of reading news for information to children and youths.

                  An applying of Buddha Dhamma, for examples, qualities of a good man, teaching by comparison to show good and bad, diligent, faithful, saving, gratefulness.  The benefits of Buddha Dhamma are making youths to know develop them-self in proper ways to grow up by body, mind,  motion and wisdom. By main activities are applied Buddha Dhamma.