The purpose of preemptive analgesia is to decrease the incidence of hyperalgesia and allodynia by reducing peripheral and central sensitization.Current knowledge of physiological mechanism,clinical application and controversy on preemptive analgesia are summarized in this review.The methods of preemptive analgesia include local infiltration,nerve block,pre-application of non-steroidal anti-inflammatory drugs,pre-application of central depressant such as opioids,NMDA antagonistic drugs,combinational analgesia measures and so on.