Many methods can be used to increase p-MNT yield in mononitration product of toluene in lab.It is found that the composition of mixed acid and of nitration method have considerable effect on isomer distribution of the product. With concentrated H₂SO₄ as substrate, toluene can be nitrated by adding diluted HNO₃ at certain temperature, and the p-MNT in the product increased by 8%,which is promising to be used in industry.