| According to the monitoring results of the water quality of harbor basin at Yantai port from 2012 to 2016, the water pollution level and its variation trend, the correlations between the monitoring items were discussed by using single factor index, Cox Stuart test and Pearson correlation analysis methods. The results showed that the water quality at the port area was generally good. The single factor pollution index of each monitoring item declined year by year, with statistical significance (P=0.05), COD was significantly positive correlated with DO, P and Cu. During the five years, pH, COD, DO，P and heavy metals did not exceed the standards， but active phosphate and inorganic nitrogen exceeded the standards at different degrees, and became the main pollution factors and the inducements of red tide risks in the sea area. |
