Keujruen Blang is a person who has particular abilities in agricultural management and arrangement and served as assistant of village head in prospering the farmers. Keujruen blang have criteria such as persevering personality, discipline, experienced and master the customary law of agriculture. This thesis describes the results of research on the customary institution's utilization of Keujruen Blang: Gabungan Perkumpulan Petani Pemakai Air (Association Of Water User Farmer; GP3A) in increasing rice production in Pidie Regency. This research is important to be carried out because the existence of ofKeujruen blang is really needed by the peasant community in the farming activities of rice fields. This study uses descriptive qualitative and quantitative methods; the research method used to create an overview of the situation or event with the accumulation of data obtained. Based on the results of the study, it is known that the role and function of Keujruen Blang in driving the cooperation of the peasant community not yet maximized. What already done is only carrying out pragmatic routine activities, so as a result it does not touch on the subject matter of the decline in the spirit of Gotong Royong (mutual cooperation). Members of Keujruen Blang are not yet aware of their main task; the motivator of the peasant community. Besides, Keujruen Blang also hasn't owned the notary registration as an institution that is legally recorded in the district. The institution does not have a clear vision, mission and goals and the lack of facilities and resources available in the district in improving the ability of the institution's capability. The non-optimal function of the irrigation system also becomes a major obstruction to the development of Keujruen Blang. Besides, other problems are related to the weaknesses of local leadership, lack of educating organizational structure, lack of government participation, and part of the substance of the customary rules are less relevant to the conditions of the peasant society nowadays. In order to minimize the problems that occur in Keujruen Blang, it requires a traditional leadership reorientation from the fixed role (the implementation of routine tasks only) to the role of a agent of change, who is able to reform the organization, improve irrigation, raise awareness of the peasants and the government, and redefinition of customary rules and Keujruen Blang.