There are many factors in Tha It community supported to be inbreeding. With its isolated location, it is the Muslim community in the metropolis and boundary with not much population as the southern border provinces. Thus, there is no choice for marriage except the people in the community. In addition, the Islamic culture has encouraged them to be isolate and get marry with the Muslim. Because Muslim men can have 4 wives, it causes the extended family. When the members of the family are increased, they separate to have their own families and when the marriage is random, some members get married together with the same ancestors. It is to say that the Thai-Muslim community at Ban Tha It can strictly maintain their ethnicity in terms of religion, beliefs, culture and livelihood among the urban society. There is some changes, but it is not significant. These factors cause the inbreeding and tend to be practice more in the future. (p.116, 165-167)