One of the key features of international law is the outstanding progress of law governing the environment in recent times. From a very reticent start with about no law at law, the global environmental law has developed an enormous complicated field encircling numerous treaties, declarations, general principles, and customary international law rules. It is not clandestine that this significant growth is due to a considerable extent, to the role played by the soft law instruments. Soft law is by its nature the enunciation of a norm in a non-binding written form and is considered to be the charters, resolutions, declarations or recommendations of world community that is not meant to be as binding as the international treaties. It is a core source of international law that has emerged and developed rapidly in the modern era of globalization, particularly to knob the sensitive issues, e.g., trade and commerce, protection of human rights, conservation of environment and so on. Though the idea of soft law has existed for years, scholars have attained at no consensus as to why do states regulate soft law or whether soft law is of a consistent logical category. To some extent, this perplexity replicates a profound diversity in the categories of global agreements and strategic situations that produce them. Despite it is accepted that soft law is a latent device in harmonizing the regime created by hard law and plays a key role in achieving fixed goals regarding the implementation of global environmental law. This article strives to provide a detailed definition of soft law as well as point outs its emergence and development. It also illustrates the legal status, impact, significance, and challenges of soft law. Furthermore, this research focuses on the role of soft law instruments in the conservation of global environment.