Parallel to the development of science and technology, wars and conflicts are also become wider and more modernized. Undoubtedly, submarines are among the armaments which are used efficiently in naval wars. The role of submarines in comparison to other war equipments has been more prominent. From the very beginning, their importance against enemy warships and commercial ships is proposed. If submarines seized a commercial ship, their action must
have been in accordance with regular procedure of inspection. This case posed serious threats to submarines at least in the water surface. Today some submarines move with nuclear fuel and Carries a variety of advanced missiles. A rule of international law in this case is not responsive at all to new issues of the contemporary world. Despite the complexity of the sub-surface combat, submarines Committed to rescue the injured and shipwreck victims and respect the other rules of humanitarian law International rules governing the conduct of submarine warfare, especially in the twenty-first century, seek to accommodate to the two branches of international law: first the neutrality law and second the law governing the conduct of military operations.