Abstract: Inflorescence is a key character affecting plant reproduction and plays an important role in plant taxonomy and phylogeny.The inflorescence types of Discorea nipponica are diverse,but relevant data are few available and often controversial.In order to distinguish the inflorescence types and characteristics of D.nipponica,a morphological observation combined with paraffin sectioning techniques was carried out to investigate the morphological characters,quantitative characters and development process of inflorescences of D.nipponica respectively.The results showed that the female inflorescence was an axillary spike,and had vestigial anther and pollen sac but didn’t produce pollen.The male inflorescence of D.nipponica showed different characteristics from the description of existing data.The male inflorescence was an infinite one composed of scorpion-tailed monochasium,which belonged to the mixed inflorescence with axillary or terminal buds developed,was shaped like spike.The leaves on some lateral branches of male plants degenerated,and axillary inflorescences gradually shortened towards the tip,presenting conical type with the terminal inflorescence.Male inflorescences had higher values than female ones in terms of average length,the number of florets,the density of florets,and flowering time respectively.The study showed that the male and female inflorescences of D.nipponica morphologies were consistent with the evolution from finite to infinite,exhibited relatively primitive features,which ensured the success of pollination and adaptability to the environment.