Background　Pain is a complex experience, which consists of not only a sensory discriminative dimension but also an affective/motivational dimension. Although the neural systems responsible for the sensory component of pain have been studied extensively, the mechanism underlying pain affect is still unclear.　Objective　The aim of this article is to explore the neural circuits and mechanisms of the negative affective component of pain.　Content　This article reviews research advances in the neuronal mechanisms underlying pain-induced aversion. It focuses on the anterior cingulate cortex,amygdala,bed nucleus of the stria terminalis and other related brain regions involved in the processing of affective component of pain.　Trend　Persistent pain is frequently associated with psychological and emotional dysfunction, studies of the neural circuits and the molecular mechanisms involved in the affective component of pain may have considerable clinical importance in the treatment of chronic pain.