Background and Theoretical Foundations: Previously, Dominik Anderska in the research entitled "coastal state’s competence in the prevention of pollution arising from ships; protection of the marine environment or Freedom of navigation" in 2017 has investigated subject of protection of the marine environment against pollution arising from ships from the coastal state, in contrast to the principle of the sovereignty with freedom of the seas but as the name implies, it focuses solely on pollution from ships and two conventions of the Law of the Sea and the MARPOL Convention Mohammadi et al. In the article entitled "Evolution of the International Legal Regime for the Protection of the Marine Environment against Inshore Pollutants; from Montego bay to Cartagena" in 1394, while emphasizing on Conversion of the problem of land-based marine pollutants to a concern for the international community and lack of The effectiveness of the provisions of general international law in combating these pollutants examines existing regional conventions that have been concluded to address gaps in general international law in this area, and examines the mechanisms contained in these instruments to identify potential gaps. Ports and their activities are the most important and significant land-based pollutants that directly or indirectly affect the marine environment. This article reviews the obligations of the port state dealing with damages that can threat environmental ports and areas outside of competence of the port state. Formerly, it was assumed that most of these damages were caused by ship traffic but now the range of environmental threats have increased and taken new dimensions. New environmental challenges of ports include issues such as the effect of climate change on ports, noise and Thermal pollution, invasive species, development of industrial and economic activities, sustainable protection of marine resources and endangerment of port biodiversity. In this study, we intend to review the environmental obligations of the port state, which include taking precautionary measures, environmental impact assessment, providing appropriate facilities, inspection of ships, reporting incidents involving oil spills, dealing with discharges at sea and dealing with Illegal, unreported and unregulated fishing, Justify the need to grant extraterritorial competence beyond the current system.

Methodology: In order to answer the question of what are the port state’s obligations to protect the marine environment, international documents including treaties and regulations of international organizations (soft law) and library data such as reliable scientific essays and articles have referred.

Findings: According to the studies, the current system of port state’s environmental obligations is largely based on territorial competence and traditional role of ports (Trade and Navigation). However, in today's world, with the emergence of new generations of ports, the functions of these strategic points have also changed, and this evolution, along with the emergence of global environmental challenges, has created an unfavorable situation for the marine environment and Despite their extraterritorial effects, they are not covered by the current port protection system.

Conclusion: Extension of the port state's competence, to consider the necessary protections and safeguards along with dispute settlement procedures at the national and international levels can fill the gaps of the flag state system. The only way to hold balance between the functions of the new generations of ports and marine conservations is to change the jurisdictions from the limited and voluntary to comprehensive and compulsory.