With developments that have been achieved in carriages of goods especially as a result of container revolution, Carriage methods have been faced with many changes and developments which one of the most important ones was international multimodal carriage of goods. Using multimodal carriage of goods by consignors, caused new challenges and issues in the areas of carriage law which available laws, regulations and legal structures were not capable to solve these problems.International Multimodal carriage is defined as the carriage of goods by two or more modes of usual transport, under a contractual arrangement from one country to another country.The purpose of this Descriptive - analytical research is finding governing regulations and rules on international multimodal carriage of goods and finding appropriate ways to determine the applicable law. There is not any integrated and specific law governing multimodal carriage of goods.This thesis tries to analyze existing conventions, including the convention on road, rail and provisions governing marine carriage contracts. Proposed hypotheses have been proved. It is derived from the results which there is not any accepted universally rule for determining an integrated governing law for multimodal carriage contracts. Also in the Iranian legal system, there is no legislation on multimodal carriage and parties to a multimodal carriage contact are unable to choose foreign law as the governing law and none of these existing conventions cannot possibly be applied as a comprehensive document that governs all issues of multimodal carriage of goods because all existing carriage conventions, apply on a particular method of carriage with just one mode which don't have qualification for applying on combination of these various modes in multimodal carriage. Application of different rules on a contract also causes legal conflicts between rules hence determining governing law has a special importance in these contracts.