Abstract The experimental tests and analysis of single fuel cell unit are performance in this research, and the electrolyte in MEA(membrane and electrode assembly) we used Nafion 112.Accroding to change several design factors and operation conditions, we can find out how important the factors affect the PEMFC power output. The experimental conditions in this study are various of type of fasten torque, flow channels, oxidizers, catalyst type and loading in cathode side, materials of electron collector, inlet gas pressure and humidification of membrane. The results can provide us references to assemble a fuel cell stack in future. PEMFC can start quickly at low temperature and achieves stable output voltage. When the 4 N-m torque is applied to fasten the reaction chamber, the contact resistance between the electrode and electron collector reaches a minimum value. The results show that when the area ratio(Af /At)is 58.41%, we can have better ratio between channel areas and contact area, and the output can be larger. We found that increasing the loading of catalyst in the cathode, the power output rises up clearly, but the loading also has a limitation. By using gold to be the electron collector, the result shows that it has better performance than using graphite, but the price is also much higher. Our experiments display that use oxygen to be oxidizer can have better performance than use air. When we heated membrane in the water at 80¢J, it can resupply the water in the membrane, remain enough humidification of membrane can be clearly helpful to the PEMFC power output, because humidification can keep the proton conductivity of the membrane in good condition. And we also found while the hot press pressure at 160atm, the performance can be better than using other pressure. Key words : PEMFC¡BMEA¡BFlow area ratio