【Abstract】 Objective To investigate the analgesic effects of intrathecal KN93 and Ifenprodil injection on pain induced by remifentanil in a incision pain model. Methods Thirty SD rats were divided randomly into 5 groups (n=6): control group (C group,n=6); incision pain group (I group,n=6); Remifentanil group (R group,n=6); KN93 group (K group ,n=6) and Ifenprodil group (F group ,n=6). These groups were to be a model of incisional pain except control group. In R group, K group and F group, remifentanil ( 0.04mg •kg-1, 40ml 1mg dissolved in saline ) needed to be infused subcutaneously 30 min. R group、K group and F group were respectively intrathecal injected 20μl DMSO(10%)、20μl KN93(50μg•20μl-1) and Ifenprodil(10μg•20μl-1).Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were tested on 24 h before and 2 h, 6 h, 24 h, 48 h after operation. Results Compared with C group, PWTL (P < 0.05 ) and PMWT (P < 0.05 ) was significantly decreased after operation on the ipsilateral side; compared with I group, PWTL (P < 0.05 ) and PMWT (P < 0.05 ) was significantly reduced in R group. After KN93 was intrathecally injected 30 min before operation, PWTL were (15.32±0.73)s、(15.79±0.32)s、(14.86±0.98)s、(14.76±0.82)s and PMWT (31.75±1.38)g、(29.27±1.16)g、(30.84±1.02)g、(30.49±1.22)g, was significantly increased (P < 0.05 ).And preoperative 30 minutes intrathecal injection of Ifenprodil, PWTL were (14.24±0.79)s、(15.33±0.29)s、(15.29±0.74)s、(15.21±0.45)s and PMWT (29.33±1.83)g、(30.22±2.12)g、(29.47±1.54)g、(30.16±1.04)g obviously increased (P < 0.05 ). Conclusion Intrathecal injection of KN93 and Ifenprodil can effectively alleviate remifentanil-induced hyperalgesia.