There are air pollution and global warming due to exhaust gas as a problem in the automotive industry. Automotive manufacturer are working on cleaning and reduction of exhaust gas, and improvement of fuel efficiency, because these regulations of exhaust gas in each country are being more severe. In the background of improvement to fuel efficiency and energy loss reduction of power transfer, the requirement for low friction, weight reduction and space saving is increasing to these reciprocating rubber seals such as automatic transmissions. In this study, to satisfy the requirement, the friction characteristic by changing rubber materials and the shape of rubber seal is investigated and studied in consideration of the temperature dependence to the friction of rubber seal. Finally, the rubber seal which provide low friction and space saving is developed.