SAM Mtases was S-adenosyl-L-methionine dependent O-methyltransferase gene.The gene has a direct effect on plant lignin,class of phenyl propane,flavonoids,alkaloids and aliphatic compounds and many other secondary metabolite syntheses.It involved in plant disease resistance,UV resistance,insecticide,antiseptic,plant hormones,growth and signal conditioning,symbionts of plants,pollen tube elongation and pollen growth of plant allelopathy reaction.This review provides an overview on the research progress in separation,classification,and functions of SAM Mtases gene.It is helpful for better understanding of its position in plant physiological and metabolic regulation.We also highlight SAM Mtases gene as a candidate gene for plant resistance and plant secondary metabolism improvement.