Abstract: Six pollution indexes were applied in the comprehensive pollution assessment of the sea areaby using the monitoring data and avoiding the limitations of single-index assessment.The six indexes are pollution index of seawater, pollution index of bathihg beach,eutrophication index and eatrophic state index.The blurred comprehensive assessment method was used in the index assessment andthe pollution state was classified as clean,lightly-polluted, moderately-polluted and heavily-polluted. In the comprehensive assessment of environment quality of sea area and pollution tendency,thesix indexes were applied altogether in the same seawater. Therefore, the assessment result was moreobjective and comprehensive.This assessment method had been applied in the environmental planningof Qinhuangdao city and a satisfied result had been ohtained.