A post-conflict country always faces a situation where the capacity of the state is questionable on recovery and transition process due to the devastation effect and horrible chaos that caused by the destructive war. In Liberia, the 14 years of civil war has breakdown more than 90% of the country capacity in various field including politic, economy, social and public services, and environment. These situation force Liberia in a very vulnerable onward failed state. Transition process became unrealistic, the maintaining of peace turn out onto more challenged, social transformation undetected, and redevelopment process turns out in the bleak shadow. As a global governance of international development network, United Nations Development Programme (UNDP) has a critical involvement of role and contribution in the area of conflictaffected. Their involvement does not only matter for the country development but rather benefited the social just transformation and the maintaining of sustainable peace. In this research, the writer would like to explore the role and contribution of UNDP and its significant effect in realizing peace, just, and inclusive society toward sustainable development in Liberia post-conflict xix 2003-2017. In order to support the objectives of the research, the writer will elaborate the concept of Global Governance from Pattberg and Dingwerth, and theory of Peace as Freedom from Jon Barnett.