For increasing soil productivity and establishing the reasonable fertilization system on yellowcinnamon soil at Huang huaihai Plain,five treatments with biochar,straw and chemical fertilizers on 3year(2014~2016)field experiment were conducted to detect characteristics of the wet sieving soil aggregates,including no fertilizer control(CK),chemical fertilizers as N,P,K(NPK),biochar adding and the chemical fertilizers(NPKB),straw returning and the chemical fertilizers(NPKS),biochar adding and straw returning with the chemical fertilizers(NPKSB).The results indicated that the fertilization treatments with organic materials(including biochar adding and straw returning)improved content of the soil aggregate in classification of bigger one(> 0.25 mm),and the stability ratio,and content of soil organic matter.Promotion of the stability ratio was ordered in extent as NPKS>NPKSB>NPKB.In the period of experiment,adding biochar gradually enhanced the content of soil organic matter annually with the order:NPKSB>NPKB,as well as NPKSB mostly advanced the contribution rate of organic matter in the soil organic matter with the classification of big one(> 0.25 mm).Therefore,in present study,the treatment of NPKSB performed the best on improving fundamental characteristic of the soil aggregates.