Because DNA degradation is mediated by secondary plant products such as phenolic terpenoids, the isolation of high quality DNA from plants containing a high content of polyphenolics has been a difficult problem. We demonstrate an easy extraction process by modifying several existing ones. Using this process we have found it possible to isolate DNAs from four fruit trees, grape (Vitis spp.), apple (Malus spp.), pear (Pyrus spp.) and persimmon (Diospyros spp.) and four species of conifer, Pinus densiflora, Pinus koraiensis,Taxus cuspidata and Juniperus chinensis within a few hours. Compared with the existing method, we have isolated high quality intact DNAs (260/280 = 1.8-2.0) routinely yielding 250-500 ng/microl (total 7.5-15 microg DNA from four to five tissue discs).