The isomeric pyrolysis mechanism of anisole was investigated using the density functional theory（DFT） of quantum chemistry.Two parallel consecutive reaction paths were determined

which involved the formation of intermediate o- and p-methyl cyclohexadienone followed by H transfer.The theoretical evidence of this important intermediate was proposed.The mechanism resulted in the formation of the two major products

o- and p-cresol.The yields of major products were almost the same

which was in accordance with the experimental fact.Kinetic analysis showed that the homolysis of O—CH3 bond in anisole was the rate-determining step

and the activation energy was 285.90 kJ8226;mol-1 at 1000 K.