Straw is one of the widely available renewable biomass resources. However, due to the diff.cult degradability of the lignin structure , wet anaerobic fermentation is generally not highly utilized fostraw at present. In this study, Phanerochaete chrysosporium , a white -rot fungus , was co -cultivatecwith anaerobic sludge under microaerobic conditions to investigate its effect on methane production fromstraw in wet anaerobic fermentation. The results showed that the substrate methane yield (75.76 ml/gVSand TCOD removal in the co-culture group increased by 45% and 37% , respectively, compared to thenon-co-culture group at 0.6 mg/L dissolved oxygen. Electrochemical analysis revealed that co-cultureeffectively increased the sludge capacitance by 183.9%. The introduction of Phanerochaetechrysosporium made the straw easier to digest and produced electroactive substances , which intensifiedthe humification process and extracellular electron transfer, and consequently increased methane pro-duction. Effective utilization of straw without pretreatment was achieved in this study , providing arefer-ence for further straw resource recovery.