Abstract: Soil polysaccharide played a very important role in aggregating agents and stabilization. Treated of soil microaggregates with periodate, all of them destroyed greatly. Compared of dispersing grouping of soil colloid, periodate oxidation was more destroying. Soil polysaccharide was very important to <10 μm and 50-250 μm microaggregates forming in cultivated land and corner, showed that perhaps there was other cementing materials playing prior actions in woodland. But in woodland 10-50 μm particles it did more work.