Abstract: Programmed cell death (PCD) is a natural cell death process controled by "death programme" coded by certain genes, occurring at certain stages of development, and commonly present in the process of plant development. PCD is the last stage of cell differentiation. The critical phase of cell differentiation occurs when the death programme is being run. PCD comprises of initiation, effector and degradation, during which the caspase family plays the key role. PCD is important in processes of plant development such as cell and tissue homeostasis and specialization, tissue differentiation and organ sculpting, and reactions to pathogens. The timing of morphological and biochemical changes are ordered during PCD. Some features of PCD in plants, including the changes in cell morphology and DNA degradation, are similar to those in animals. But PCD in plants is different from that in animals in that the products from PCD in plants can either be phagocytosed by other cells or used for constructing the cell's own secondary wall.