Identification method of plant species mainly done according to their morphologic characters can not be applied to close species or their parts of tissue.However,development of DNA molecular markers during the past more than 10 years made it possible.This paper studies the application of RAPD molecular marker in distinguishing 3 different species following Castanea mollissima,C.henyi and C.seguinii.The results shown that different special conservative segment of each species was enlarged with primer B07(GTCCACACGG).Respectively three species-specific DNA segments weighted of 2 050 bp,900 bp and 1 500 bp.This method can be used in species identification widely.