Necroptosis is a novel programmed cell death mechanism which is caspase independent. It is mediated by specific signaling via a death receptor ligation. Necroptosis usuaUy arises when the apoptotic Pathway is inhibited, and is characterized by a necrotic morphology. Recently many reports have revealed that necroptosis is precisely regulated by a cellular signaling pathway, like apoptosis. Receptor interaction protein kinase 1 and receptor interaction protein kinase 3 kinases are the key regulators of this alternative cell death mechanism. MLKL plays an important role in TNF-induced programmed necrosis pathway. In this paper physiological function and molecular mechanism were reviewed.