Function design of electronic chart display and information system-polar is studied based on the overall technology requirement of navigational charts in polar navigation. Firstly function requirements of ECDIS-Polar is analyzed based on the influence analysis of polar navigation environment and technology characteristics and demand analysis of project implementation. Then overall principles are presented and detailed function module architecture of ECDIS-Polar is constructed by borrowing general framework of conventional ECDIS. Lastly key technologies and solutions of ECDISPolar development are suggested. The research results provide a conceptual system design for ECDIS-Polar，which would be useful for the development and improvement of ECDIS-Polar.