The improvement of ship performance and propulsive efficiency has been addressed in this article. In this research, the comparative study has been investigated for a certain passenger vessel with the research results of Stapersma and Woud in their research “Matching Propulsion Engine with Propulsor” that has been published on Journal of Marine Engineering & Technology. After that, the marine propulsion plant system will be researched to enlarge the operational ranges between marine propeller-shaft system- marine diesel engines. A case study of passenger ship has been applied from this research namely Sea life Legend 02 in Quang Ninh province, Vietnam. The marine propulsion plant system of passenger ship will be designed in the Simulink/Matlab platform. Each functional block will be presented for the devices of the marine propulsion plant system, including the diesel engine, generator, shaft system, and marine propeller. The improvement of marine propulsion plant will be conducted on this proposed numerical model. The collected results have been shown the priority features of the marine propulsion plant system and they are fundamental to enlarge the propulsion performance of ship. The research results would be analyzed and validated with the actual marine propulsion plant system. This article is significant for ship-operators and ship-owners in the management of marine propulsion plant system for ships nowadays.