According to the analysis of elements,compounds,and grain size of 128 samples,we study the flood variation indicated by sediment in floodplain in the Jingyang reach of Jinghe River during deposit of floodplain. Results show that the contents of Mn,Ni,Cu,Zn,Ga,Pb,Ba,Rb,V,Al₂O₃,Fe₂O₃,and K₂O change obviously in the profile. Each component changes obviously in the entire profile,which can clearly reflect the variations of flood and precipitation with high resolving power. The profile may be divided into 18 sediment layers,indicating 18 flood events at different scales and 18 years with much precipitation. The finer grain size is,the higher contents of Mn,Ni,Cu,Zn,Ga,Pb,Rb,V,Al₂O₃,Fe₂O₃,and K₂O are and the lower content of Ba is,which indicates small flood intensity,low flood level,and less precipitation in deposition. In contrast,the coarser grain size is,the lower contents of Mn,Ni,Cu,Zn,Ga,Pb,Rb,V,Al2O3,Fe₂O₃,and K₂O are and the higher content of Ba is,which indicates high flood intensity,high flood level,and more precipitation at deposition. The small changes of two or more elements,compounds,and grain size in the thin layer formed in the same sediment layer in the 18 floods indicate two or more flood peaks frequently appeared in the period of most floods. Sediment in the 14th,12th,13th,8th,5th,and 1st layers in floodplain in the Jingyang reach of Jinghe River reflects that annual precipitation increases in the whole basin and annual rainfall is greater than 800 mm.