Stipa zhadaensis L.Q. Zhao & K. Guo sp. nova and S. turkestanica Hack. var. diyaensis L.Q. Zhao & K. Guo var. nov. (Poaceae) from Tibet, China, are described and illustrated. Stipa zhadaensis appears to be most closely related to S. roborowskyi of Stipa sect. Barbatae. It can be distinguished by the lax panicle with inclined branches exserted from uppermost leaf sheath at maturity, 20–28 mm long glumes with a scarious apex that is acuminate into a fragile filiform extension, and a 6.0–9.0 cm long awn. The differences between S. turkestanica var. diyaensis and S. turkestanica var. turkestanica are that the former has a somewhat longer anthecium (11.0)12.0–13.0 mm vs. (9.5)10.8–12.1(13.5) mm), longer awn (17.0–20.0 cm vs. (8.8)11.8–15.8(18.4) cm), and a column that is to first bend hairy and to second bend plumose vs. glabrous or scabrous).