Abstract: In the present paper，one new species and three new varieties of Gramineae are described from Xizang（Tibet），China．They are Orinus tibeticus N．X．Zhao，Stipa capillacea Keng var．parviflora N.X.Zhao et M．F．Li，Deyeuxia con ferta Keng var.guoxuniana N.X.Zhao et M．F．Li and Bromus staintonii A.Melderis var．guoxunianus N.X．Zhao et M．F．Li；and Catabrosa aquatica（L．）Beauv．from Xizang is a new record．

Key words: Gramineae