Fuel cell vehicle as a hot topic has been studied for a long time, how to monitor and get reliable performance data will be very helpful for its further improvement. In this paper an online monitor system, where EP100 MCU of Freescale, LabVIEW software of NI Co. and RS232 serial port are applied, is introduced for a fuel cell commuter. This system includes program operation area, mode display area, data monitor area, alarm area and curve display area. It can detect the fuel cell commuter's performance in real time when the vehicle is running, and store the relative data conveniently and reliably.