Abstract: The changes of phenolic acid and its effects on the amount of fertilizers uptake and yield of summer corn are studied being caused by decaying wheat straw in the field.The results show that phenolic acid content is higher in the soil with returning wheat straw,the highest concentration of phenolic acid is observed at about the 40th day after the returning of wheat straw,the phenolic acid content is lower in the soil with fertilizer application,the influences of phenolic acid on the yield and the uptake of N and P is insignificant,but it can inhibit the growth of seedlings' root system.