Abstract: In order to study the distribution characteristics and sources of hydrocarbons in the surface sediments of Sanniang Bay in Guangxi Province, the authors have collected five surface sediments samples in October 2019 and analyzed their polycyclic aromatic hydrocarbons (PAHs) using GC-MSD method. The results showed that the PAHs content was 37~241.8 ng/g, which was generally in a low level, but it markedly increased in recent years. The component analysis on PAHs source indicated that the main source is combustion source and mixed oil source. The ecological risk assessment of PAHs was carried out by the effect interval method, and it was found that the PAHs content was in low risk level. The comprehensive study shows that the overall ecological environment of Sanniang Bay is good, but the impact of human activities on PAHs is obvious and needs to be paid continuous attention.