Abstract: The characters of reproductive organ have been the main evidences for the classification of Poaceae, but they are not totally equal in the taxonomic value because of the differences of their dependencies in morphological trait, growth position, developmental degree and environmental alteration. In order to overcome the various drawbacks in applying character, author discussed the taxonomic values of main macroscopic characters in the paper, and summarized their ranks suitable for differentiating taxa. In them, the type of inflorescence, position of spikelet, shape of floscule and fruit, and so on are of high value to classification, and usually suitable to the taxa above the rank of tribe;the shape of inflorescence, arrangement of spikelet, type of fruit, and so forth are slightly low in value, and usually suitable to the taxa from genus to species;the length and thickness of inflorescence, rachilla, palea, and the like are low in value, and usually suitable to the species or infraspecific taxa.

Key words: Poaceae, character of reproductive organ, taxonomic value, review