〔Abstract〕 Objective To investigate the ameliorative effect of vitamin D on sciatic nerve chronic compression injury(CCI) rats and its regulatory effect on nuclear factor κB(NF-κB)/cystathione-β-synthase(CBS)-hydrogen sulfide(H2S) system. Methods Fifty rats were randomly divided into five groups: control group,model group,vitamin D group,activator group,and activator + vitamin D group,with 10 rats in each group. Except for the control group,the rats in the other groups underwent sciatic nerve ligation to establish the CCI model. The vitamin D group received intraperitoneal injection of 500 mg/kg vitamin D,the activator group received intraperitoneal injection of10 mg/kg NF-κB activator lipopolysaccharide,and the activator + vitamin D group received intraperitoneal injection of 500 mg/kg vitamin D along with 10 mg/kg lipopolysaccharide. The control and model groups received intraperitoneal injection of an equal volume of saline,once per day for 2 weeks. The following parameters were compared among the groups: paw withdraw thermal latency(PWTL),mechanical withdrawal threshold(MWT),serum 25-hydroxyvitamin D3[25(OH)D3]levels,H2S content,calcitonin gene-related peptide(CGRP),prostaglandin E2(PGE2) levels,and the expression of vitamin D receptor(VDR),NF-κBp65,and CBS proteins in the L4-L6 dorsal root ganglia of rats. Results Compared with the control group,the model group showed decreased PWTL,MWT,25(OH)D3 levels and VDR protein expression,while H2S content,CGRP and PGE2 levels,and NF-κBp65 and CBS protein expression significantly increased(P 3 levels and VDR protein expression(P 2S content,CGRP and PGE2 levels,and NF-κBp65 and CBS protein expression significantly decreased(P3 levels and VDR protein expression,and decreased H2S content,CGRP and PGE2 levels and decreased NF-κBp65,CBS protein expression(P 3 levels and VDR protein expression,while H2S content,CGRP and PGE2 levels,and NF-κBp65 and CBS protein expression significantly increased(P 2S signaling pathway.