Abstract: The reproductive capacity of mammals usually declines with age accompanied by the deterioration of oocyte plasmids.Epigenetic changes are the signs of aging in mammals. Aged oocytes are caused by aging or delayed fertilization after ovulation, and histone modification is an important reason for the aging of oocytes.The changes of histone acetylation and methylation in aged oocytes will affect the maturation of oocytes and the development of subsequent embryos, resulting in poor development during somatic cell nuclear transfer.In practical production, older animals are prone to produce aged oocytes, which reduces their reproduction ability and leads to the decline of economic benefits of livestock and poultry breeding. In order to increase the reproductive capacity of older animals and increase the economic benefits of livestock farming, the author mainly explained the changes of histone modification in aged oocytes from the aspects of histone acetylation and methylation, aiming to provide a reference for a better investigation of the mechanisms of oocyte aging.