The monitoring data of nitrogen and phosphorus in eutrophication were collected and compiled, which was from 2 national routine monitoring sites in Raohe River of Poyang Lake from 2007 to 2011, and the frequency of nitrogen and phosphorus pollution in the monitoring section of Le’an River and Chang River of Raohe river was analyzed. The results showed that the monthly frequency of ammonia nitrogen pollution of Ⅴ and bad Ⅴwater quality in Chang River section of Rao River was 2.17%, and Ⅳ water quality was 6.52%. In addition, The monthly frequency of ammonia nitrogen and phosphorus composite pollution of bad Ⅴwater quality in Le’an River section of Rao River was 28.26%, Ⅳ and Ⅴ water quality was 2.17%. Finally, the cause of the time and space changes of nitrogen and phosphorus pollution was analyzed in Rao River section based on the above research foundation.