Ballast water in ship operation is essential for a safe voyage. However ballast water can contain unwanted organisms that are the cause of disturbing the ecosystem by the transfer of potential invasive species. To prevent the destruction of the environment, the International Convention for the Control and Management of Ship`s Ballast Water and Sediments(BWM Convention) was adopted in 2004. BWMS (Ballast Water Management System) has been developed to prevent the transportation of organisms to another region in order to fulfill the requirements IMO (International Maritime Organization) regulations. Nowadays there are about 50 approved Ballast Water Management Systems of various types globally. The most common BWMS types are UV (Ultra Violet), Electrolysis and Ozone. Among these types there are many difficulties in determining the optimum type of BWMS which can be suitable for the user and designer`s requirements. The main objective of this research is to select the best BWMS type by using AHP. To apply AHP, the most important criteria for the BWMS development are derived by users and designers. From our results, we can give a guide BWMS type to the developers of BWMS.