The transport of radioactive material by sea is strictly governed by the international regulatory regime which is established by both IAEA and IMO. Nonetheless, although the current regime is well established, due to catastrophic results of potential accident, it is essential to keep identifying areas where further enhancement is necessary. This paper reviews the current regulatory regime governing sea transport, such as IAEA Regulations, IMDG Code and INF Code. Then, specific requirements of the INF Code are analyzed for the purpose of identifying areas where improvement is necessary from the perspective of ships. Through this analysis, this paper identifies areas to be improved and proposes to improve the INF Code which can supplement the current regulatory regime for sea transport of radioactive material.