Aim To investigate the changes of phosphorylated p38 mitogen-activated protein kinase(p-p38MAPK)in the spinal cord following chronic compression of dorsal root ganglion(CCD)in rats, and to explore the correlation between chronic neuropathic pain and p38MAPK.Methods The animal model of neuropathic pain following chronic compression of dorsal root ganglion was established.36 male Sprague-Dawley rats were randomly divided into Naive group(n=4),Sham group(n=16),CCD group(n=16).Sham group and CCD group were also divided into 5,7,14 d and 21 d group respectively(n=4),Western blot analysis was used to investigate the expression of the phosphorylated active form of p38MAPK (p-p38MAPK) in the spinal dorsal horn in rats after CCD.Results p-p38MAPK protein was expressed in spinal cord among all three groups,but there were no significant differences between Naive group and Sham group.Compared to Naive and Sham group, rats in CCD group showed significant increase of the expression of p-p38MAPK protein in spinal cord.Compared with that of Sham group,protein expression of p-p38MAPK in cytosol in the spinal dorsal horn in 5,7,14 d and 21 d of post-surgery increased respectively 138.1%(P