PM2.5 samples were collected to characterize organic compounds of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in Xiamen, China in 2013. The concentrations of PM2.5, PAHs and n-alkanes were 55.53 µg m–3 and 22.14 µg m–3, 15.73 ± 6.25 ng m–3 and 5.65 ± 3.73 ng m–3, 148.57 ± 36.84 ng m–3 and 97.53 ± 67.46 ng m–3 in winter and summer, respectively, demonstrating that higher pollutant levels in wintertime. Benzo[e]pyrene (BeP) was the most abundant PAH, accounting for 32% and 26%, respectively, of the total quantified PAHs in winter and summer, followed by coronene (Cor) and phenanthrene (Phe). Five-rings PAHs was the most dominant group, contributing 50.8% and 44.1% of the total quantified PAHs in winter and summer, respectively. Two peaks were shown among the homologue distributions of n-alkanes, and the dominant components enriched in high molecular weight fraction. Meteorological parameters had stronger impacts on atmospheric PAHs levels in summer than that in winter, while the most significant parameter was relative humidity (RH), followed by temperature. Diagnostic ratios indicated that PAHs in Xiamen were mainly contributed by petroleum combustion in the two seasons, and the concentrations of n-alkane were mainly influenced by anthropogenic sources. The annual values of benzo[a]pyrene (BaP) equivalent concentration and incremental lifetime cancer risk (ILCR) were 0.83 ± 0.63 ng m–3 and 7.17 × 10–5 and 1.11 × 10–4 ng m–3 and 3.29 × 10–5 in winter and summer, respectively. The findings illustrated that the overall exposure risk to PM2.5-bound PAHs did not exceed an alert level in Xiamen, but the higher risks were still shown in winter.