In this study, sources of PAHs in coastal sediments of Shandong Peninsula were apportioned using the chemical mass balance (CMB) model, and source apportionment of carcinogenic and mutagenic potencies was conducted combining CMB with the formula of benzo(a)pyrene carcinogenic equivalent (BaP TEQ ) and BaP mutagenic equivalent (BaP MEQ ) concentration. Total concentrations of sixteen PAHs in sediment ranged from 181.2ngg −1 to 303.6ngg −1 , and concentrations of eight carcinogenic PAHs (cPAHs) varied from 98.8ngg −1 to 141.1ngg −1 . The BaP played a dominant role for carcinogenic and mutagenic potencies of PAHs, although the IND showed the highest concentration level. The vehicular sources made the highest contribution to BaP TEQ (57.7%) and BaP MEQ (55.5%), while petrogenic source, the highest contributor for PAHs (39.4%), provided the lowest contribution to BaP TEQ (1.1%) and BaP MEQ (1.5%). Besides, the ecotoxicological evaluation, based on Sediment Quality Guidelines (SQGs), showed low ecological risks generally.