Abstract: As a branch of genetics,epigenetics is relative to the inheritable expression change of gene or protein,without altered gene sequence,its research objective is gene modification,including DNA methylation,histone acetylation,gene marker and so on.In the recent years,with the studying development,the application on curing tumor has been achieved success in DNA methyltransferase and histone acetyltransferases inhibitors.Here we reviewed the mechanisms of the above mentioned epigenetic modification,their roles in tumor initiation,and the progresses in tumors therapies.