IMO(International Maritime Organization) introduces more strengthen regulation to deal with pollutant issues from ships. A hybrid power system, consisting of plural power sources such as an internal combustion engine, a renewable energy, battery, etc., providing power to ships is considered as one of promising solutions. This lab. has done research on marine battery system and hybrid powered electric propulsion system by analyzing power characteristic of power sources and performance and reliability test depending upon various system configurations, power characteristic analysis of marine power sources.