Water is a source of life;it is customary to say.The veracity of this old assertion is no longer to be demonstrated in our contemporary world where water has become one of the most coveted resources on the planet so that its control and management become the primary concern of life of Human.Thus,some argue that water is a rare commodity in the sense that freshwater management becomes serious problems for users.This assertion is both true and false in the sense that,like other natural resources,fresh water is unevenly distributed in space and there is strong growth in water demand,whence its alleged scarcity.But this rarefaction cannot be retained as a factor of problem-related to its management.The issue of watercourse management can be explained by the contemporary challenges faced by States,the way in which water resources are used（often abusive）and irresponsible attitude of some States Through unilateral actions on the watercourse shared by several countries.The law of international watercourses had been previously concerned with the only question of navigation as evidenced by the Vienna Congress on the Internationalization of shared rivers and lakes of 1815 and the General Act of Berlin which extended internationalization to the great African rivers,as was the case of Niger River.Indeed,this thesis will be devoted entirely to the legal regime governing the equitable sharing of the Niger River basin under its legal,political and institutional aspects.This great river of West Africa,which originates in the mountainous massifs of "Futa Jalon"（Guinea）,is the third largest river in Africa with a length of 4200 km.The Niger River basin,which irrigates much of West Africa,is shared between nine countries riparian countries of the main river,its tributaries and sub-tributaries,namely Benin,Burkina Faso,Cameroon,Chad,Cote d’Ivoire,Guinea,Mali,Niger,and Nigeria.With an estimated population of over 112 million,the Niger’s transboundary basin covers an area estimated at 1.1 million km2.Naturally,water defies borders and serves as a link between the states it crosses.Naturally,water defies borders and serves as a link between the states it crosses.This is all more evident for the water resources of Transboundary Rivers,which require close cooperation between the countries that shared them and the riparian states of the Niger basin have understood that very early.Thus,in the 1960s,the independent states of the Niger River Basin decided to coordinate their efforts to exploit the natural resources of the basin,first and foremost water.To this end,the Niamey Act concerning Navigation and Economic Co-operation between the States of the Niger Basin was signed on 26 October 1963.It was replaced by the Niamey Agreement on the Niger River Commission and Navigation and Transport on the Niger River signed on 25 November 1964,the purpose of which was to "encourage,promote and coordinate studies and programs for the development of the resources of the basin".The Niger River Commission was replaced by the Niger Basin Authority（NBA）,established by the Convention of 21 November 1980 in Faranah（Guinea）and revised on 29 October 1987 in Ndjamena,Chad.It should be noted that in recent decades,the development of the use of the resource goes beyond the question of navigation or transportation to be more interested in other elements such as hydroelectric generation particularly consumptive purposes such as irrigation or water supply,has necessarily led to the adoption of various treaties or agreements related to water resources shared to ensure a more concerted and peaceful management.To meet these new challenges,the riparian countries were quick to develop an adequate legal framework to prevent the risks of tensions linked to increased resource requirements at the level of all States.To this end,the member states of the NBA have initiated the process of the shared vision for the sustainable development of the Niger basin since 2002.This process resulted in the production of three main documents,namely the Sustainable Development Action Program（SDAP）with a 2008-2027 investment plan（IP）and the Niger Basin Water Charter and its different annexes.This latter document,drawn up in reference to the Helsinki Convention of 17 March 1992 related to the protection and use of transboundary watercourses and international lakes and the Convention on the Law of the Non-Navigational Uses of International Watercourses,adopted in New York on 21 May 1997constitutes genuine reference legal framework in terms of peaceful and integrated management of shared watercourses for sustainable development.Indeed,given the concerns of basin States concerning the equitable and sustainable management of the resources of the basin,this thesis will focus on the equitable and reasonable sharing of the benefits generated by the river for sustainable development and non-confrontational management of the basin.Basin,as stated in the Paris Declaration of 2014.In this perspective,research will focus on the political,legal and institutional issues that contribute to the equitable sharing of the water resources of the basin between the riparian States and will contribute to it through proposals based on the law of international watercourses.