The goal of this study was to identify the relative contribution of fossil and non-fossil contributions to PM_2.5 carbonaceous aerosols (CAs) in PM_2.5 pollution events. To achieve this, the pollution characteristics and source apportionments of CAs using radiocarbon (¹⁴C) and organic tracers (anhydrosugar) were determined during a long-lasting winter haze episode (Jan. 13–24, 2018) in Xiangyang, central China. Non-fossil sources (biofuel, biomass burning, and biogenic emissions) contributed 74 ± 3% and 35 ± 2% to organic carbon (OC, 20.7 ± 6.79 μg/m³) and elemental carbon (EC, 6.48 ± 1.79 μg/m³), respectively. During the winter haze episode, CAs were derived from primary biofuel and biomass burning-derived OC (POC_bb, 27.3 ± 4%), secondary biofuel and biomass burning-derived OC (SOC_bb, 26.7 ± 5%), fossil sources-derived EC (EC_f, 15.4 ± 3%), secondary fossil sources-derived OC (SOC_f, 14.7 ± 1%), biofuel and biomass burning-derived EC (EC_bb, 8.4 ± 2%), primary fossil sources-derived OC (POC_f, 5.5 ± 1%), and secondary biogenic sources-derived OC (SOC_bio, 2.0 ± 1%). Biofuel and biomass burning contributed more to PM_2.5 pollution compared to traffic exhaust, which indicated that the public and government should pay attention to control biofuel and biomass burning in Xiangyang, central China.