The psbL-psbJ region of chloroplast DNA (cpDNA) of 8 and 2 Hordeum species or subspecies from China and other countries, respectively, were investigated by PCR amplification and direct sequencing. It was indicated that the length of the psbL-psbJ region in all Hordeum species or subspecies was 365 bp, and no variable site was observed. The sequences of psbL-psbJ region were compared with that of rye (Secale cereale L. ) , wheat ( Triticum aestivum L. ) , rice ( Oryza sativa L. ) and maize (Zea mays L. ). The length of psbL gene was 117 bp in all materials, and no variable site was detected. The length of psbJ gene was 123 bp in all materials, and six variable sites were found. The length of psblL-psbJ inter-gene region was 125 bp in all materials except rice, while it was 126 bp in rice. There have 8 variable sites in psbL-psbJ inter-gene region. Using maize as outgroup, phylogenetic relationships were estimated by neighbor-jioning method. It suggested that the species or subspecies of Hordeum were genetically related to rye and wheat, which also belong to the tribe of Triticeae, while rice was related to maize.