Based on field test，the effects of mutifunctional soil amendments on soil physiochemical properties and economic benefits of corn were studied in a sandy soil in Hexi area． The results show that the effects of the amendments followed a descending order as: cow dung ＞ furfural residue and SAR ＞ fertilizer ＞ poly-vinyl alcohol． The combination of A₁B₁C₂D₃E₃(cow dung 7． 82 t，furfural residue 6． 00 t，special fertilizer 1． 04 t，polyvinyl alcohol 0． 09 t，insurance agent 0． 05 t) displayed the best amending effects． The application amounts of the muti-functional soil amendments were found correlated positively with the values of soil porosity，aggregate structure，volume of water，organic matter，available phosphorus，available potassium，and EC，and negatively with the values of bulk density and pH value． Marginal yields and profits decreased with increasing application amount of the multi-functional soil amendments． The pure interest rate decreased as an extra amount of 3． 75 t/hm² was applied over the base amount of 15． 00 t/hm²． Based on statistical regression，the optimal application would be 15． 00 t/hm² with a theroetical corn yield of 7． 03 t/hm²，which agreed well with the field tests．