It was believed that apoptosis was the only programmed cell death in the development and homeostasis of vertebrate. Meanwhile, necrosis was considered to be un­programmed. However, growing evidences have demonstrated that some types of necrosis can also be regulated by signaling molecules, and these types of necrosis could be defined as programmed necrosis or necroptosis. In this review, the morphological characteristics of necroptosis, and the relationships between necroptotic signaling pathway and the immune system’s function and inflammatory response are summarized.