A simulation experiment was carried out to improve aggregate structure of sandy yellow soil that distributes widely in Chongqing city.We designed the material made of straw,bentonite and PAM and detected its effects on improving the aggregata sturcture of sandy soil.The results indicated that: The proportion of 1~5 mm sandy soil aggregate increased in the presence of improved material,and would be different with different improved material,and also increased with the content of improved material and PAM(<2%...