To determine the stable carbon isotopic compositions (δ¹³C) and source apportionment of carbonaceous components in Taiyuan, PM_2.5 samples were collected using medium flow samplers (TH-150C) during 4 months in 2014. The δ¹³C values of organic carbon (OC) and elemental carbon (EC) in PM_2.5 were determined using an MAT-251 gas mass spectrometer with a dual inlet system. Moreover, δ¹³C_EC values from industrial and domestic coal combustion were synchronously measured. In March, May, August, and December, the mean δ¹³C_OC values were −23.9 ± 0.9‰, −25.2 ± 0.2‰, −25.3 ± 0.6‰, and −22.9 ± 1.0‰, respectively; the corresponding δ¹³C_EC values were −23.8 ± 0.8‰, −24.2 ± 0.5‰, −25.3 ± 0.4‰, and −23.8 ± 0.3‰; and the corresponding δ¹³C_TC values were −23.8 ± 0.7‰, −24.8 ± 0.2‰, −25.3 ± 0.4‰, and −23.2 ± 0.6‰. Notable differences were observed in temporal distributions of stable carbon isotopic compositions of OC, EC, and total carbon (TC). The heavier δ¹³C_EC values in December and March was caused by increased coal combustion and C4 plant burning during the heating season. The δ¹³C_EC value was heavier than the δ¹³C_OC value in May, whereas the opposite was true in December. The δ¹³C_OC value may have been changed in atmospheric reactions during secondary organic aerosols formation in May and photochemical aging in December. There was almost no difference between δ¹³C_OC and δ¹³C_EC in March and August. Source apportionment suggest that the EC sources in Taiyuan during the 4 months were different. EC in March and December was mainly due to fossil fuels (93.8%) and C4 plant burning (6.2%), EC in May was mainly affected by industrial coal combustion (50.0%) and vehicle exhaust (50.0%), and EC in August was the comprehensive result of fossil fuels (63.6%) and charcoal burning (36.4%). These results may enhance understanding of the sources of carbonaceous components in fine particles and may provide valuable data for environmental management.