An electronic ballast and magnetic ballast are two major types of ballasts used in HID(High Intensity Discharge) lamp. Compared with magnetic ballasts which can last for over 30 years and are recyclable at the end of their long lifetime, electronic ballasts have very short lifetimes due to the use of the electronic devices. In this paper, we developed a magnetic ballast for dual lamps and analyzed electrical characteristics and efficiency. As the experimental results, we confirm that the magnetic ballast for dual lamps makes it possible to effectively reduce current, active and reactive powers than conventional ballast.