By means of cDNA amplified fragment length polymorphism(cDNA-AFLP) technique, a fragment P1708 was amplified from Polima cytoplasmic male sterile Chinese cabbage-pak-choi (Brassica campestris L. ssp. chinenesis Makino, syn, B. rapa L. ssp. chinenesis) ‘Bpol97-05A’. RT-PCR showed that this fragment was specifically expressed in male sterile material. Sequencing and BLAST search in GenBank database indicated that P1708 had 100% homolog with chloroplast ndhJ-trnF gene region except a 54 bp insertion. Gene specific primer pairs were synthesized according to ndhJ-trnF gene region and two fragments about 1 900 bp were amplified respectively using genomic DNA templates of Polima cabbage and male fertile oilseed rape. The sequencing results showed that the gene region ndhJ-trnF of Polima cabbage contained two 54 bp repeats and some variation sites. The repeat part shared the same sequence as trnF gene except three bases at 5′ ends. For the insertion of 108 bp sequence, a new open reading frame was created.