This study estimated the initial volume mixing ratios of the ambient VOCs measured from 18 April to 31 July 2021 in Linfen, Shanxi Province, using a photochemical age-based parameterization method, and corrected photochemical loss effects.Positive matrix factorization (PMF) was used to conduct the initial-data source apportionment. The results showed that the average volume mixing ratio of total VOCs (TVOCs) during the study period was 17.1×10^-9. The average initial volume mixing ratio of TVOCs in the daytime was 27.2×10^-9, with chemical loss of 10.6×10^-9 and loss rate was approximately 39.0%. Compared with other VOC groups, alkenes had the highest loss rate (66.0%). The chemical losses of isoprene (3.16×10^-9), 1,3-butadiene (1.27×10^-9), and ethylene (1.19×10^-9) were higher than any other species. During the ozone pollution (OP) period, the chemical loss of TVOCs was 15.1×10^-9, which was 1.6times higher than during the non-ozone pollution (NOP) period. During the OP period, the loss rate of alkenes was the highest (81.7%) than the other VOC groups. The losses of isoprene, 1,3-butadiene, trans-2-butene, and trans-2-pentene were 5.05×10^-9, 1.85×10^-9, 1.59×10^-9, and 1.10×10^-9, respectively, substantially higher than any other species. The PMF apportioned results based on the initial volume mixing ratios (i.e., IC-PMF) showed that petrochemical-related enterprise emissions (36.4%), natural gas (17.2%), the mixed source of diesel vehicle emissions and solvent usage (12.9%), gasoline vehicle emissions (9.6%), liquefied petroleum gas (8.6%), biogenic emissions (8.6%), and combustion sources (6.7%) were the main contributors to the ambient VOCs in Linfen during the study period. Compared to the PMF apportioned results based on the observed volume mixing ratios (i.e., OC-PMF), the contribution of biogenic emissions was underestimated by 83.3%, which was substantially higher than those of other sources; followed by the mixed sources of diesel vehicle emissions and solvent usage (22.2%) and the petrochemical-related enterprise emissions (19.7%). Meanwhile, the IC-PMF results suggested that the sources with higher contributions during the OP period were the petrochemical-related enterprise emissions and biogenic emissions, accounting for 24.1% and 21.7%, respectively. According to the IC-PMF apportioned results, the estimated results using the ozone formation potential (OFP) model showed that petrochemical-related enterprise emissions was the highest contributor to the OFP, with the contribution of 50.7% to the total OFP, followed by biogenic emissions (24.8%) and the mixed source of diesel vehicle emissions and solvent usage (10.4%). The emission sources with higher contributions to the OFP during OP period were biogenic emissions and petrochemical-related enterprise emissions, reaching 52.6% and 27.8%, respectively.