The adoption of territorial integrity principle by the Organization of African Unity was not an easyrndecision. Since the continent was extremely divided by the limitless interests of European colonialists,rnthere were politicians and scholars who were calling for revising and redefining these boundaries. Withrnassumption of the tangibility of colonial boundaries and the commitment to save the continent fromrndisintegration during independence, the organization adopted the principle which accepts colonialrnadministrative boundaries as international boundaries of African newly independent states.rnThe principle however did not escape from criticism in the past decades for its failure to prevent boundaryrnconflict and ensure peace and stability as it was initially aspired. In this paper, the researcher hasrnendeavoured to examine the general nature of African boundary related treaties, the shortcomings of thernapplication of the principle and the new challenges of the boundaries and the principle.rnThe finding of the research shows that the African colonial boundary treaties are questionable as to theirrntangibility and certainty. The boundaries are results of continuous multilateral and bilateral treaties ofrncolonialists. Their certainty is very questionable. The purposes and objectives of the treaties of thernboundaries were ensuring competing interests of colonialists against the interest s of Africans and theirrnlegality is also challengeable. Implementing these over century old boundary related treaties at these daysrnare becoming difficult due to their vagueness and contradiction to the practical situation of borders. Thernapplication of territorial integrity /uti possidetis principle adapted by OAU to identify and transfer therncolonial boundaries found to be illusive, incomplete and vulnerable to unrestricted interpretation of ICJ.rnThe principle is critically tested by new challenges such as secession and demarcation in its failure tornaccommodating new developments around borders since independence.rnThe issue is continental and further research is very necessary. The practice of the application of thernprinciple (ut ipossidetis) should not be the only boundary establishing mechanism and it need to bernequally supported by other asserting mechanisms principle such as effective control, publicrnadministration, etc. Expanding democracy and encouraging the application of internal self- determinationrnis critical to avoid secession before it became threat of boundary. The need to border integration shouldrnnot be postponed not only to reduce boundary problems but it is a base for other integrations. ICJâ€™srninterpretation trend focusing only on seeking the purpose and intention of parties of the treaty needrnintervention and change. There has to be a kind of effective type of interpretation since the disputants ofrnboundaries were not parties of the treaties.rnKey terms: boundary, uti possidetis, ICJ, critical-date, secession, territorial integrity