Compensation of transboundary environmental damages, especially in the case of hazardous activities is one of the complex issues of international environmental law. Sometimes in spite of taking all preventive measures, some authorized and legitimate activities of States that are generally dangerous can cause irreparable damages to other subjects of international law and especially to the environment. For as much as these activities are not prohibited, the traditional systems of civil responsibility are not effective when dealing with the compensation of environmental damages. Therefore, the development and codification of particular system of compensation for environmental damages is inevitable. The result of international community's effort in this context is the approval of draft of International Law Commission titled Draft Principles on the Allocation of Loss in the Case of Transboundary Harm Arising out of Hazardous Activities, with Commentaries 2006” declaring that the State is responsible and obliged to prevent and the operator of hazardous activity is obliged for compensation of the damages under circumstances to commit such acts