A total of 46 surface soil samples collected from the experimental area, buffer area, and core area of the Yellow River Delta Natural Reserve (YRDNR), China, and an adjacent area outside the reserve were analyzed for 23 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 87.2 to 319 ng/g for ∑23PAHs and 79.2 to 311 ng/g for ∑16PAHs with average concentrations of 133 and 119 ng/g, respectively. Pearson correlation analysis implied that the total polycyclic aromatic compound (PAH) concentrations had a significant positive correlation with the total organic carbon content on the condition that four sites with abnormal values were removed. Low molecular-weight 2- to 3-ring PAHs predominated in the present study. Source diagnostics based on PAHs isomer ratios, principal component analysis, and multiple linear regression suggested that petroleum contributed most to the PAH contamination in the YRDNR, whereas a potential toxicity assessment using BaPeq indicated that the four dibenzopyrenes were the major carcinogenic PAH contributors in the area under investigation, although their concentrations only represented a small proportion of the total PAH concentrations.