A method for extractING 
genomic DNA of Lonicera 
japonica Maxim belongs to field of 
molecular biology. The method mainly comprises the following steps: firstly, 
cell walls and 
cell membrane are brokenso that 
DNA is fully released into buff; secondly, the interference of 
protein, 
polysaccharide, 
pigment and other impurities was eliminated; finally, 
DNA degradation is prevented. The sample was treated with SET 
nucleus separation buffer, which could separate the 
nucleus from the secondary substances such as polysaccharides and polyphenols in the supernatant, PVP added in the 
grinding process andbeta-Mercaptoethanol, can effectively prevent the oxidation of polyphenols, 
chloroform / 
isoamyl alcohol extraction, the addition of diluted CTAB to remove polysaccharides. The leaves of Caprifoliaceaeplants are rich in carbohydrates and polyphenols, These substances not only affect the extraction of 
DNA, but also affect the activity of Tag 
enzyme in PCR. By this method, DNA with high yield and good quality can be obtained. DNA electrophoretic bands are clear and bright, and there is no 
tail-
trailing phenomenon, which can meet the further research at 
molecular level.