自身免疫病是一类严重危害人类健康的慢性复杂性疾病，包括器官特异性自身免疫病和系统性自身免疫病等20余种疾病。表观遗传学是研究DNA序列未改变而基因表达发生变化的一种可遗传改变，其调节机制主要有三种：DNA甲基化、组蛋白修饰以及微RNA调节。此文综述了这三种调节机制对基因表达的影响及在自身免疫病发病中所起的作用。

 Autoimmune diseases are serious threats to human health, which are generally considered as complex and chronic diseases, including organ specific autoimmune diseases and systemic autoimmune diseases of more than 20 kinds of diseases. Epigenetics is defined as the investigation of heritable changes in gene expression that occur without a change in DNA sequence.There are three major epigenetics mechanisms: DNA methylation, histone modification and microRNA regulation. In this article, the three mechanisms are reviewed and their effects on gene expression and roles in autoimmune diseases are discussed.