The gene BnC3H cloned from ramie and its recombinant proteins expressed in Escherichia coli were analyzed to reveal the enzymatic characteristics and the metabolic mechanism of regulating the lignin in ramie. The open reading frame (ORF) sequence of BnC3H gene was obtained by RT–PCR, and then the cloned genes of BnC3H were inserted into vector pET–22b. The recombinant plasmids pET–22b–C3H were expressed in the prokaryotic expression system after its transformation into E.coli BL21. The result showed that the BnC3H ORF sequence was 1 536 bp and encodes 511 amino acids. The relative molecular weight is 57 800. The optimum concentration of IPTG was 1 mmol/L, results of SDS–PAGE showed that the specific fusion protein was successfully induced by IPTG.