Biodegradation mechanisms and microbial functional diversity during coupled p-nitrophenol(PNP)and p-aminophenol(PAP)degradation were studied in a bioelectrochem-ical system.PNP in the biocathode and PAP in the bioanode were almost completely re-moved within 28hr and 68hr respectively.The degradation followed the steps including hy-drating hydroxyalkylation,dehydrogenating carbonylation,and hydrolating ring cleavage,etc.Metagemomic analysis based on the KEGG and eggNOG database annotations revealed the microbial composition and functional genes/enzymes related to phenol degradation in the system.The predominant bacteria genera were Lautropia,Pandoraea,Thiobacillus,Ig-navibacterium,Truepera and Hyphomicrobium.The recognized biodegradation genes/enzymes related to pollutant degradation were as follows:pmo,hbd,&ppo for phenol degradation,nzba,amie,&badh for aromatic degradation,and CYP&p450 for xenobiotics degradation,etc.The co-occurrence of ARGs(antibiotic resistant genes),such as adeF,MexJ,ErmF,PDC-93 and Escherichia_coli_mdfA,etc.,were annotated in CARD database during the biodegrada-tion process.The Proteobacteria&Actinobacteria phylum was the primary host of both the biodegradation genes&ARGs in this system.The microbial functional diversity ensured the effective biodegradation of the phenol pollutants in the bioelectrochemical system.