Abstract: The authors had a field trip to wetlands of Wu River in Linyi, Shandong Province, collected samples to determine and analyze water quality indexes, such as N, P, COD and BOD. The experimental results showed that the constructed wetlands could remove 55% of TN, 76% of COD and 70% of BOD, but only had a low removal rate of P. The average concentration of TN and TP of eight sample points were 26.55 and 0.125 mg/L, respectively. According to the standard of eutrophication degree analysis (Thomas), the TP and TN of Wu River wetlands are in the rich degree of eutrophication level. Therefore, the eutrophication degree of constructed wetlands of Wu River is high overall, indicating that wastewater treatment does not develop well.