The operation characteristics of proton exchange membrane fuel cells with the channel width of 1mm and 2 mm under a medium-pressure are addressed，and the effect of temperature on the operation characteristic is investigated in detail.The results show that fuel cell with a 2 mm channel width can realize the long time operation in a closed-ended situation.The voltage of the 1mm width cell can drop from 0.7V to 0.5V in 3min，while the 2 mm width cell can last for more than 53min.Moreover，the temperature has a significant effect on the performance，the voltage of the 1mm width cell can drop from 0.69V to 0.5V in less than 1.7min.The resistance of the cell is increasing with the temperature，but the amplitude is smaller in high temperature.