Abstract: Based on the data of permanganate index of the Qijiang River monitored during the last 7 years,and applying the method of prediction of the grey system theory,a model of grey prediction of permanganate index of Qijiang River was designed,and its permanganate indexes of the years 2006,2007 and 2008 were found to be 5.3,5.4 and 5.4 respectively.