Objective:To investigate the role of heme oxygenase-1(HO-1) in molecular mechanism of experimental allergic encephalomyelitis (EAE). Methods: Seventy-eight healthy female Wistar rats were randomly divided into 3 groups(n=26): rats in control group received no treatment; rats in EAE group were induced with complete Freund's adjuvant and Guinea pig spinal cord homogenate(CFA-GPSCH); and rats in pyrrolidine-dithiocharbamate (PDTC) group received PDTC (100 mg/kg), a specific inhibitor of NF-kB, 1 h before and after(once a day for 7 d) CFA-GPSCH treatment. HO-1 mRNA expression were analyzed with reverse transcription polymerase chain reaction(RT-PCR) on 1 d,7 d,14 d,and 21 d after EAE induction, respectively. The relationship between HO-1 and symptoms of EAE was also investigated. Results: The expression of HO-1 mRNA was very low in the brains of the control group (0.27?0.05), whereas enhanced gradually with onset and development of EAE in EAE group, peaked on d 7 (1.11?0.12), kept at a high level till d 14(1.06?0.18) and decreased on d 21 (0.37?0.1). HO-1 mRNA expression change was in parallel with severities of EAE. In PDTC group,the EAE symptoms were mitigated markedly and the expression of HO-1 mRNA reduced noticeably compared with that of EAE group. Conclusion: Brain HO-1 mRNA expression may play an important role in the pathogenesis of EAE,and application of some inhibitors of NF-kB may be one of the potential therapies for prevention and treatment of EAE.