Abstract: Spinal anesthesia can inhibit the stress response of the body to surgical pulling and other stimulation due to the blockage of the sympathetic nerve. Meantime, it can also reduce the secretion of adrenal cortical hormone, thyroxine and catecholamine, and lead to the fluctuations of the blood glucose level. Sympathetic block can induce the dilatation of peripheral veins, decrease the blood return and lead to hypotension. As an endogenous ligand of angiotensin Ⅱ type 1 receptor-associated protein （APJ）, Apelin is widely distributed in the body and involved in the regulation of blood pressure and blood glucose in multiple organs and tissues in different patterns. Apelin plays a critical role in the incidence and development of metabolic syndromes, such as diabetes mellitus and hypertension, etc. In this article, the function of Apelin and the relationship between Apelin and blood pressure and blood glucose under subarachnoid anesthesia were reviewed.