This thesis is concerned with the organizational development of aboriginal groups in Ulai. Taiwanese aborigines are minorities in Taiwan. They have suffered many difficulties such as poverty, unemployment, little education in their lives. With the trend of organizing groups to pursue rights in society, Taiwanese aborigines have learned to protect their rights and to solve their problems through organizations. Therefore, this research tries to present the situation and characters of groups in Ulai by interviewing the elite. Additionally, the information on the organizations and on the population of Ulai is compared with this of Taipei County and the whole country, in order to realize the standard of the groups in Ulai. The conclusions are: 1.The number of aboriginal groups has been rising in Ulai but there is no extremely large group. The reason is that the population of Ulai grows very slowly and the groups cannot get as many members as they want so that segmentary differentiation is not found. On the other hand, stratificatory differentiation is discovered in the most two large groups. 2.The financial resources of the groups are overlapped. The main financial resources are fees, donations, subvention, and interest incomes. 3.The groups interact and cooperate with one another. However, they usually interact according to the local government's invitation but not because of their own decision. The groups sometimes join forces to offer activities as a result of lacking money or socializing. 4.Most of the activities held by the groups in Ulai are associated with learning and entertainment. Nevertheless, the groups also provide irregular service for people when they need help. Also, we find that the aboriginal groups in Ulai are becoming specialized. The categories are getting varied. 5.There are more and more people who live in Ulai and they are better educated. Besides, the financial situation is getting better over there too. Those improvements make people have better abilities to organize groups. Still, the slow growth of population is an obstacle to the development of the groups in Ulai. It probably hinders further expansion of the aboriginal organizations. 6.There are spontaneous aboriginal organizations in Ulai. Although their functions are the same as the government¡¦s work, their existence helps the government serve the people more efficiently.