The application of fuel cell is increasing in the last years mainly due to the possibility of high efficient decentralized clean energy generation. Fuel cells are a potential power source for electric vehicle or distributed power generation system. In electric vehicle application, a high power boost dc-dc converter is adopted to adjust the output voltage, current and power offuel cell engine to meet the vehicle requirements. The major challenge of designing a boost converter for high power application is how to handle the high current at the input and high voltage at the output. In this paper, a high voltage ratio interleaved boost dc-dc converter is proposed for stepping-up the voltage on high power application. A prototype of converter system was built. The experimental waveforms of the high voltage ratio interleaved boost converter are presented