Abstract: Based on the data of water quality,sediment,and biological indicators of Xincun Port's mariculture area from 2011 to 2018,the single factor pollution index,comprehensive environmental quality index and eutrophication index were used to evaluate the comprehensive environmental quality status of the region,and the Seasonal Kendall test and Spearman correlation coefficient method were used to quantitatively analyze the change trend and correlation of water quality factors.The results showed that:1) From 2011 to 2018,the overall water quality of Xincun Port's mariculture area was excellent,which could meet the functional requirements of the aquaculture area.2) The eutrophication status was good.Since 2011,it had been at an overall oligotrophic and mesotrophic level,and only became eutrophication in 2016.3) Water pollution was dominated by organic pollution,followed by phosphorus nutrient pollution,while heavy metal lead,arsenic pollution and pesticide residues in seafood also required attention.4) Pollution from ship navigation had increased and pollution from aquaculture had been reduced.By studying the changes of environmental quality in the sea area of Lingshui Xincun Port in the past eight years,we could provide scientific basis and intellectual support for the rational development,utilization and protection of Xincun Port.