Abstract: The eutrophication status of Hexi Reservoir was analyzed and evaluated using comprehensive nutrition state index method. The results showed that the comprehensive nutritional status index of Hexi Reservoir as a whole tended to increase from 2014 to 2018. However,the trend variation was not significant. The nutrition classification was at medium eutrophication level. According to the analysis of the eutrophication causes of Hexi Reservoir,the measures and suggestions for protecting the water environment of Hexi Reservoir were put forward.