Epigenetic modifications, including DNA methylation, histone modifications, RNA epigenetics and nucleosome remodeling, are important for gene transcription, but such modifications do not change the coding sequence of the gene. Although these events are heritable, they are potentially reversible, thus opening up opportunities for the therapy of cancer. So epigenetic modifications have been thrusted into the forefront of new drug discoveries. Current knowledge suggests that the agents that intervene epigenetics by "turning back on" silenced genes may represent a significant advancement in treating many forms of cancer. In this review, we summarized the research progress of epigenetic gene regulation and the proteins which could read epigenetic codes. And the relationship between epigenetics and cancer was discussed comprehensively.