Obective To explore whether spinal microglia contributes to postoperative hyperalgesia in incisional rats with nicotine abstinence.　Methods　Forty-two SD rats were randomized into one of the 3 groups of rats. IP Group（n=18） which was divided into 3 sub-groups according to the executed time， six rats in each group. The rats underwent incisional pain model. N+IP group（n=18） which was divided into 3 sub-groups according to the executed time， six rats in each group. The rats underwent incisional pain model after subcutaneous injection of nicotine for 7 d. M group（n=6）： besides all the procedures conducted in the N+IP group， the rats were given intraperitoneal injections of minocycline 100 mg/kg one hour before surgery. For all rats， mechanical withdrawal threshold （MWT） and thermal withdrawal latency（TWL） were determined on the 1st， 2nd， 3rd， 5th and 7th day after surgery. The rats in IP group and N+IP group were executed after NWT and TWL tests on the 1st， 3rd and 7th day after surgery， and then the lumbar enlargement of spinal cord L4?蛳6 were collected. Ionized calcium binding adapter molecule?蛳1（IBA?蛳1） positive cells were determined by immune?蛳histochemical method.　Results　Compared with IP group， MWT and TWL in N+IP group were significantly lower on the 1st， 2nd， 3rd， 5th and 7th day after surgery（P<0.01）. Compared with N+IP group， MWT［（28.1±1.4） g vs （22.3±2.4） g］ and TWL［（7.5±1.3） s vs （5.2±1.2） s］ in M group were significantly higher on the first day after surgery（P<0.01）， whereas no differences were found on the 2nd， 3rd， 5th and 7th day after surgery（P>0.05）. In IP group， the number of IBA-1-positive cells in spinal dorsal was significantly higher on the 3rd day than those on 1st and 7th day after surgery （P<0.01）. Compared with IP group， the number of IBA-l-positive cells in N+IP group was higher on the 1st， 3rd and 7th day after surgery（P<0.01）.　Conclusions　Nicotine exposure could activate spinal microglia which might contribute to postoperative hyperalgesia in incisional rats with nicotine abstinence.