The water quality of Shanmei Reservoir was assessed using a comprehensive index based on data from 2004 to 2006. The main pollution factors in the reservoir, from most to least severe, are total nitrogen, total phosphorus, fecal coliform group, permanganate index, dissolved oxygen, NH+4-N, and biological oxygen demand. Overall, the water quality of Shanmei Reservoir is at level Ⅱ, meeting the corresponding water function standards. However, three pollution factors, total nitrogen, total phosphorus, and fecal coliform group, exceed the standards. Total nitrogen is particularly bad, reaching level Ⅴ, while total phosphorus and fecal coliform group are at level Ⅲ. The reservoir shows signs of eutrophication due to the worsening total nitrogen and increasing total phosphorus levels.