Undergraduate thesis aimed to answer the reason why thousands of Indonesian citizens came and settled in the region of Mindanao, Southern Philippines, which started from 1969 to the present even though their existence was very controversial to many parties around. One of the factors that makes Indonesian citizens alienated by the surrounding community even though they have lived for years in the area is due to lack of clarity regarding their citizenship status and the absence of a clear identity from them. To puzzle out the problem, this undergraduate thesis utilized the theory of Bilateral Cooperation and the Role theory by Mohtar Mas'oed. This research found out that there was a shift in population from Indonesia to the Mindanao region of the Southern Philippines because Indonesia and the Philippines had long established strong partnerships with the proximity of the two which were only taken four hours from Marore Island to Mindanao Island by boat. In addition, The Consulate General of the Republic of Indonesia in Davao City as fully responsible for the existence of Indonesian citizens in Mindanao has sought to resolve this problem. Some of these efforts include: (1) The Indonesian Consulate General conducts data collection which is assisted by the Philippine government and UNHCR and (2) The Indonesian Consulate General conducts socialization and create a Congress of the Diaspora of Indonesia- Southern Philippines, where the congress aims to provide basic knowledge about Indonesia that they had forgotten while living in the Philippines for decades. In influencing the determinants, The Indonesian Consulate General has succeeded in resolving this case, there are some citizens who have been officially declared citizens of Indonesia has been granted a free passport and visa and returned to Indonesia according to the area they came from when in Indonesia.