ObjectiveTo develop a method for the extraction and examination of total DNA of Yunnan Cannabis. MethodThe improved isolation method of SDS were used to extract the total DNA of Cannabis, and DNA were examined by PCR. ResultsThe DNA polymorphism has been examined successfully by the cannabis sativa special primers which had been screened. ConclusionThe DNA of cannabis can be extracted and detected efficiently by this method, which provides the basis for the identification of different species of cannabis.