To obtain high quality genomic DNA from Euonymus japonica Thunb, different DNA isolation methods were studied. A modified CTAB DNA extraction method was got by comparing different methods,such as SDS method, CTAB method, high salt low pH method and modified CTAB method. The results show that isolated DNA possesses the characters of high purity (A₂₆₀/A₂₈₀ is 1.84) and high yield (213.5μg/g fresh leaves). So the method can isolate DNA effectively from hydroxybenzene and sugar abundant medicinal materials.