Abstract: AIM: In order to identify “Beimu” by molecular biology technology, the extraction method of genomic DNA and PCR amplification were studied. METHODS: The genomic DNA extraction methods by SDS, CTAB and DNA_zol reagent were compared, so were DNAs from samples treated with different methods. The effects of DNA quality, annealing temperature and activity of Taq DNA polymerase on PCR products were studied also. RESULTS: The SDS method is simpler and cheaper. The fragment of genomic DNA extracted from fresh sample was longer and purer. The annealing temperature and activity of Taq DNA polymerase showed little effect on PCR amplification, while the quality of DNA affected the PCR amplification directly. CONCLUSION: By extracting genomic DNA from fresh sample and PCR amplification, a specific band was obtained.