Modified micro-MEA is developed and employed to evaluate the electrocatalytic performance of Pt/C and PtRu/C. Firstly, micro-MEA displays better electrocatalytic performance including lower onset potential and higher peak current in comparison with traditional glass carbon electrode (GCE), because that micro-MEA effectively avoids interferences from specific adsorption of bisulfate ions on platinum and improve mass transfer of the fuel. Then, evaluation of the effect of Nafion content and methanol concentration on the MOR performance of Pt/C and PtRu/C is carried out. The results reveal that Pt/C shows optimized performance with 30 wt% Nafion in low concentration methanol (0.5-1 M), while PtRu/C displays best performance when Nafion content was adjusted to 10 wt% because of easier formation of complete proton pathway and triple-phase boundary (TPB) compared to Pt/C, indicating that the optimized in-situ work condition is significantly different for different electrocatalysts. Our work in this paper indicates that micro-MEA as a kind of in-situ characterization method can give more precise electrocatalytic performance of electrocatalysts close to work condition and facilitate their sieving and further application in DMFC. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.