SETD2/HYPB has been known as a histone H3K36 specific methyltransferase. However, its roles in physiology such as development and cellular function remain unclear. In this study, using mESCs as cellular model, we show that Setd2 mainly regulates differentiation of murine embryonic stem cells (mESCs) towards primitive endoderm. This study aimed at exploring how did Setd2 regulate primitive endoderm. differentiation.