MADS-box genes form a large family of transcription factors and play important roles in flower development and organ differentiation in plants. In this study, a cDNA, encoding a typical MIKC type MADS protein with 245 amino acids was isolated from kenaf flower. Database BLAST search analysis of the full deduced protein sequence yielded high homology with other MADS-box proteins. The sequence was designated as HcMADS-box and submitted to the Genbank with accession number of HQ315826. Subsequently, a 2338 bp genomic DNA fragment of HcMADS-box gene was isolated by PCR. Compared with its cDNA sequence, 7 introns and 8 exons were found in HcMADS-box gene. The nucleotide sequences had no difference between cytoplasmic male sterility (CMS) and maintainer lines. Southern blotting analysis showed it contained one copy in the genome. Phylogenetic analysis suggested the HcMADS-box belong to E-type MADS-box gene corresponding to the ABCDE model. The expression pattern of HcMADS-box was investigated by RT-PCR. Both in CMS and maintainer lines, the highestlevel of HcMADS-box gene expression was found in floral tissues but very poor in vegetable organs. Further comparing HcMADS-box gene expression pattern in CMS and maintainer line, the expression level was found to be reduced in the CMS lines notably.