Abstract: In order to study effect of oil pollution on ecological environment in coastal waters of Guangdong Province, the oysters (Crassostrea rivularis) from Guangdong coast during 2001-2010 were collected and the contents of total petroleum hydrocarbons (TPH) in the organisms were determined by spectrofluorometry. A method to grade the ecological risk caused by oil pollution was built for finding the relations between the oil pollution and the Guangdong marine economy. The results indicate that TPH content in oyster samples ranged from < 0.2 to 36 mg·kg^-1 (wet weight) with an average value of 9.4 mg·kg^-1, which was significantly higher than their average content of 6.7 mg·kg^-1 detected from 1989 to 1992. Along the coastal waters of Guangdong Province, the highest content of TPH presented in the Pearl River Estuary, which was significantly higher than that in eastern or western coastal part (P < 0.01). The TPH was slightly higher in the eastern coast (8.7 mg·kg^-1) than in the western coast (7.6 mg·kg^-1), but the difference was not significant (P>0.10). During the decade, the annual average of TPH content in coastal waters of Guangdong Province had taken a V-shaped variation depending on the time changing. The frequencies of low or medium level ecological risk were 83.3% and 16.7%, respectively, indicating that low ecological risk was generally caused by oil pollution, while medium ecological risk occurred in a very low probability. Annual average of TPH content (dry weight) during 2001-2010 was negatively correlated to annual oil consumption during 2000-2009 (r=-0.738, P < 0.02), but positively correlated to annual oil pollutants discharge during 2000-2009 (r=0.752, P < 0.02). Temporal variation and spatial distribution of TPH content in the oysters were closely related to the oil pollution control from land source, industrial structure and industry layout along the coastal waters. In addition, it was also significantly influenced by the dramatic increase of coastal industries such as ship building, offshore engineering and oil mining.