PC-SOD (Lecithinized superoxide dismutase) is 4 molecules of a lecithin derivative-bound SOD, an enzyme of scavenging superoxide anion (O2-). Intravenous administration of PC-SOD (1 mg/kg) promoted the recovery from spinal cord injury (SCI)-induced motor dysfunction, when evaluated by BBB (Basso Beattie Bresnahan) score. The potency of PC-SOD was superior to that of methylprednisolone (MP) (30 mg/kg), which is now in clinical use. PC-SOD as well as MP inhibited SCI-induced neutrophil infiltration. The damaged area in PC-SOD treated spinal cord was less, as compared to that in MP-treated one. PC-SOD had only a little effect on gene expression of inflammatory cytokines and neurotrophic factors. However, MP suppressed not only gene expression but production. Different from MP, PC-SOD significantly promoted the production of GDNF. These data indicated that one reason why PC-SOD was superior might be ascribed partly to the increase of GDNF production.