Abstract: The morphological structure of vegetive organs in Polygonum cuspidatun Sieb.et Zucc.was studied by the phytotomy method in this work.The result shows that the morphology of the buds of terrestrial stem is different with that of rhizome,enwrapping by the squama leaves for the latter and not doing for the former,with more amylum in the cells of the buds of rhizome.Structures of the adventitious roots,terrestrial stems and subterranean stems are similar to that of dicotyledons,having the secondary growth and primary growth.Also,it was observed that the roots is tetrarch and the periderm of the adventitious roots and subterranean stems developed,with diversiform leaves structure on which there existed not only nail eglandulose hairs but also capitate glandular ones.Especially,the extrafloral nectary in the bases of the petioles was firstly found.

Key words: Polygonum cuspidatun Sieb.et Zucc;vegetative organs;anatomical structure;extrafloral , nectaries