Food, Clothing and Shelter, nature has given some basic needs to human for survival. One of the needs which is paramount to humans is water. Flowing water in form of river, lake crosses boarder of one state to another. When water crosses one country and enter the into the territory of another then inadvertently it leads to disputes. Every nation ends up claiming ownership over the water. For resolving the disputes, nations use successful machinery of international law i.e., diplomacy. Diplomacy is an art and skill of managing the international relations through peaceful way like negotiation, discussion, mediation. Water diplomacy is an innovative approach and instrument to resolve water issues at transboundary scale when conflict arise in sharing water resources. It may contribute to solve variety of water conflict like fresh water, industrialisation, irrigation, transboundary water management etc., The United Nations in 1997 introduce convention to resolve water problem. The paper will discuss the same. The great part of the earth i.e., South Asia facing same issue since an age, the researcher will highlight the same. As of now water comes under international law and international diplomacy is playing vital role here, this paper discusses the review of water diplomacy further, this paper pointed out the situation of water conflict in South Asian countries like, India, China, Pakistan, Nepal and Bangladesh.