We analyzed content and distribution,dynamic change,and trophic type of nitrogen and phosphate,and evaluated environmental quality in the Yellow River Estuary and adjacent waters based on the monitoring data from 4 cruises in May 2008,August 2008,May 2009 and August 2009.The result indicated that nitrogen level was high in the Yellow River Estuary and adjacent waters,but phosphate level was low in most sea areas.The trophic type was in potential eutrophy limited by phosphorus.Trophic status of the sea areas was in mesotrophy to eutrophy.The eutrophy level in May was higher than in August,and it was higher in coastal and southward sea areas.The water quality of the sea areas was initially polluted in May 2008 and in August 2009,but it became better in August 2008 and in May 2009.