In order to investigate the differential expression of the genes related to cytoplasmic male sterility in Chinese cabbage (Brassica campestris L. ssp. Penkinsis), a modified RNA fingerprinting technique was developed to compare the difference in the total RNA from flower bud of Chinese cabbage among cytoplasmic male sterility (CMS) lines, maintainer lines and F1 hybrids. Four stably differential fragments S47-412, S93-622, S176-343 and S199-904 were amplified, cloned and sequenced with primers selected from 186 random primers. Based on the nucleotide sequence of the four differential fragments, four pairs of specific primers were designed to validate the differential fragments. The validation showed S47-412 and S93-622 were false positives and S176-343 and S199-904 were confirmed by PCR with the specific primers. Sequence analysis revealed that both of two differential fragments had strong homology with the nucleotide sequence of orf224/atp6 site of Polima CMS and the nucleotide sequence of S176-343 and S199-904 had a superposed region. All these indicate that the two fragments probably have strong relationship with cytoplasmic male sterility in Chinese cabbage.