Abstract: According to the comparative analysis result of historical heavy metals contents in the surface sediments from the Jiulong River Estuary and Xiamen Bay from 1980s, the average value of heavy metals contents in this sea area was established, and the overview of heavy metals distribution characteristic has been made. Besides, the background level of heavy metal element contents was determined according to the need of potential ecological risk index method, it provides the reference data of average value and background level for further research and evaluation. Combined with the survey data in August, 2016, the integrated risk evaluation results indicated an unoptimistic situation of this sea area, the eastern of Xiamen Sea Area mainly belonged to low ecological risk, Jiulong River Estuary mainly belonged to heavy ecological risk, and the rest of Xiamen Bay mainly belonged to moderate ecological risk.

Key words: Jiulong River Estuary, Xiamen Bay, surface sediments, heavy metals, background level, integrated ecological risk assessment