The performance of polymer electrolyte membrane fuel cells(PEMFC) has investigated by varying composition of the electrodes which consist of catalyst and proton-conductive ionomer. Their performance appeared to be significantly affected by the total amount and the distribution of the ionomer in the electrodes. The best performance was obtained when the ionomer content was 1/3 of the total amount of the catalyst(by weight); but, 1/4 of the ionomer was inside the catalytic layer and 3/4 at the interface between the catalytic layer and polymer electrolyte membrane. The performance of the electrodes was also influenced by the preparation method of catalyst inks which were composed of solvent, catalyst powders and ionomer solution, in such a manner that the so called "colloidal method" showed better results than did the conventional "solution method". The former method appeared to secure continuity of the ionomer network and also a higher porosity in the catalytic layer, resulting in a higher proton conductivity and a less mass transfer resistance. The effect of preparation methods was investigated by employing the various electrochemical analysis techniques.