Abstract: To investigate the aerobic and anaerobic microbial degradation of polycyclic aromatic hydrocarbons (PAHs) in riparian wetland soil, a microcosm incubation-based experiment combined with chemical analysis and 16S rRNA amplicon sequencing analysis was employed. The aerobic and anaerobic degradation rates of naphthalene, fluoranthene and pyrene and their key degradation microorganisms in a wetland soil sample of the JialingRiver, as well as the effects of different electron receptors on the microbial degradation of PAHs under anaerobic conditions, were explored. The results showed that the dissipation rates of naphthalene, fluoranthene and pyrene were 70.6%, 61.5% and 41.41% under aerobic conditions after incubation for 35 days, respectively. Under anaerobic condition, the dissipation rates of naphthalene, fluoranthene and pyrene were 76.01%, 72.59% and 42.57%. The addition of NO3- significantly promoted the anaerobic degradation efficiency of all the three PAHs, whereas the addition of SO42-inhibited the PAHs degradation. The addition of ferrihydrite (Fe(Ⅲ)) stimulated the degradation of pyrene, whereas the addition of goethite (Fe (Ⅲ)) stimulated the degradation of fluoranthene.The results of quantitative analysis of functional genes showed that the abundance of phnAc and bssA significantly increased under aerobic andanerobic conditions after the addition of PAHs. The sequencing results showed that the main aerobic PAHs-degrading bacteria were MND1, Arenimonas, Mycobacterium and Burkholderiales, whereasthe dominant PAHs-degrading bacteria shifted to Geobacteraceae, Hydrogenophaga and Bacteroidetes_vadinHA17 under anaerobic condition. The potential PAHs-degrading bacteria communities were influenced by the addition of different electron acceptors.Lysobacter and Arenimonas were significantly stimulated by the addition of NO3-. These results showed that the microbial PAHs degradation in the riparian wetland soil was jointly driven by different aerobic and anaerobic PAHs-degrading bacteria. The nitrate or Fe(III)-dependent anaerobic microbial PAHs degradation may have important contributions to the removal of PAHs in riparian wetland soils.