Abstract: The genus Oryza belongs to the tribe Oryzeae, subfamily Oryzoideae of the grass family Poaceae, consisting of more than 20 species. Among the species, about half are polyploids. These polyploids include BC, CD, HJ and HK genomic constitutions and are distributed in Asia, Oceania, Africa and Latin America. Because of its economic and theoretic significance, Oryza has attracted enormous attentions from scientists worldwide. Cor-respondingly, many research data are accumulated for the polyploid members in the genus. In this paper, we have reviewed the history of Oryza, especially the study of the polyploids. Based on our recent molecular studies on the origin and phylogeny of Oryza species, we summarized the current status of the investigations on the classifica-tion and phylogeny of the polyploid species. In addition, we discussed the perplexity and future direction of the studies on the Oryza polyploids.

Key words: Oryza, polyploid, historical perspective, perplexity