To identify the characteristics and sources of carbonaceous aerosols in an urban area (UA) and rural area (Guihua Township, GH) of Nanchong City, organic carbon (OC) and elemental carbon (EC) were measured in fine particulate matter (PM_2.5) samples collected from December 2014 to April 2016. The results showed that the average concentrations of PM_2.5, OC, EC, and secondary organic carbon (SOC) in UA were 66.23±3.68 μg/m³, 13.34±0.93 μg/m³, 3.80±0.29 μg/m³ and 10.05±0.83 μg/m³, respectively, and those in GH were 60.13±4.28 μg/m³, 13.82±1.03 μg/m³, 3.92±0.44 μg/m³ and 10.23±0.90 μg/m³, respectively. The seasonal variations in PM_2.5, OC, EC, and SOC in UA and GH were similar, with the order summer < spring < autumn < winter. The average OC/EC ratio in UA was 4.72±0.31, and that in GH was 5.14±0.38. In addition, K⁺, Pb, Zn, and As were positively correlated with OC and EC. This result indicated that biomass burning, fossil combustion, and motor vehicle exhaust within the Sichuan Basin were the main sources of PM_2.5 in Nanchong City. The poor meteorological diffusion conditions prevalent for pollutants were the main reason for the high concentration of carbonaceous aerosols in Nanchong City.