Abstract: This paper was a case study on the operation effect of the Xiaohegou constructed wetland in Qionghai wetland, Sichuan province. The condition of the aquatic plants in constructed wetlands was investigated, including the resource allocation, distribution, plant density and wilting level. According to the analysis of the removal rate of pollutants in the constructed wetland system, the wetland operation effect is obtained. The results showed that the removal rates of COD, TN, TP and NH₃-N in the wetland were 23.9%, 62.6%, 79.7% and 58.7%, respectively.The removal efficiency of pollutant was better in the dry season. The main factor affected the efficiency of pollutant removal was the residuals of plants that have not been cleared in time in the constructed wetland. It is recommended that regular cleaning and maintenance should be performed to ensure the normal operation of the constructed wetland.