Seven samples(five varieties of Phyllostachys nidularia and two affined species) are tested with RAPD in order to assess their genetic relationship.The results indicate:①The Phyllostachys nidularia can be distinctly distinguished from two affined species within the same genus.There exists a genetic varia- tion in the of varieties Phyllostachys nidularia.②RAPD markers can be a powerful tool for genetic research on the infra-species of bamboo.