The parabrachial nucleus，encircling the superior cerebellar peduncle，is divided into several subnuclei according to its configuration and cytoarchitecture. The obvious structural heterogeneity of PBN leads to its functional diversity，which makes it as one of the most interesting topics in neuroscience. PBN has been proved to play an important role in multiple interreacted physiological processes，including maintaining homeostasis，as⁃ cending sensory information，reordering stress ⁃ related behaviors，and regulating sleep/wake cycle. For instance， hypothermia occurs when one is in hypometabolism，which in turn reduces metabolic rate. Cross ⁃linking between the functions of PBN suggests that it not only serves as a relay station for sensory information，but also has internal anatomical connection and functional integration among subnuclei. Currently，the mechanism of cross ⁃ linking among subnuclei and the commonality of regulating the same physiological function are the focal points. This review aims to document the physiological functions of neurons in PBN so that it can provide a theoretical basis for further understanding what regulates specific physiological function.