Electrolyte species and concentration have an effective influence on the size distribution of soil particles.Five electrolytes as NaCl,CaCl2,MgCl2,MgSO4 and seawater (a mixture of various electrolytes) were used with different concentrations in these experiments.From particle-size cumulative curves,it is obvious that flocculation of soil is intensified with the addition of certain salinity concentration until there are limited effects.The particles smaller than 25 μm were easier to flocculate than larger ones,which is evident in the figures.It was measured the impact of electrolyte species on size distribution under the same concentration,and we found the order of impact is:CaCl2 ＞ MgSO4 ＞ MgCl2 ＞ NaCl.