Background　Chronic pain, which involves unclarified pathophysiologic mechanism, is not simply a continuum of acute pain. Studies on functional modification in central nervous system of chronic pain have provided various modulatory factors and evidences of changing in perception and behavior.　Objective　The present review aims to summarize the modifications occur in the context of structural remodeling and reorganization of nociceptive pathway in the process of forming chronic pain.　Content　In spinal cord, long?蛳term nociceptive inputs may be associated with modifications in synapses, cells and circuits. It can induce remodeling of these micro anatomy structure and potentially contribute to the sustaining status of chronic pain.　Trend　The structural remodeling of central nerve system in chronic pain may lie the pathological mechanism of pain sensation after the relieving of nociceptive input and provide a more effective treatment method for chronic pain.