The Caspian Sea and Persian Gulf are faced to environmental pollution. The (ROPME) covers eight states the Regional Organization for Protecting the Marine Environment that Joined force in 1978 to adopt the Kuwait Regional Convention for Cooperation on the Protection of the Marine Environment from pollution, otherwise known as the Kuwait Convention and four associated Protocols. The five countries bordering the Caspian Sea have a Convention for Protecting Caspian Sea (CEP), and related four Protocols. This study shows there are many differences of regulation are between the two conventions. The main differences are pollution controls, biodiversity management and control of the hazardous waste.