Histone methylation, including arginine methylation and lysine methylation, is one of the important area of epigenetics research. There is growing evidence that the abnormity of histone methylation is closely related to the process of carcinogenesis, and this methylation is a reversible modification process. Further studies on the histone methylation would not only help to better understand the physiological mechanisms of gene expression, regulation and genetics, but also throw light on the research of diagnosis, prevention, treatment and prognosis of tumor and other serious diseases. In this paper, the histone methyltransferase, demethylase and their relationship with the process of carcinogenesis were summarized.