Based on the statistical results of flood disaster losses in 1991～2016，this article uses matter-element analysis to evaluate and grade flood disaster losses，and analyzes the changes of rainfall indicators that affect flood disaster losses.The results shows：1） Every year，Jiangxi province suffers from flood disaster losses.The years of minor disasters，major disasters，and severe disasters accounted for 65%，19%，and 16%，respectively.The years of severe disasters were mainly concentrated in the 1990s.2）The main rainfall indicators that affect the degree of change in flood loss are annual rainfall，rainfall during the flood season，and monthly rainfall coefficient of variation.Flood damage losses and rainfall indicators are directly proportional.3）Affect by various engineering measures and nonengineering measures，under the same frequency of rainfall，after 2000，especially after 2010，the degree of flood damage was greatly reduced compared with the 1990s.