Abstract: The effects of different degrees drought stress on growing development, chlorophyll content, proline content, MDA content and root activity were researched by application ornamental grass Pennisetum setaceum'Rubrum'as the test material.The results showed that there was significant difference in proline content between treatment 5% polyethylene glycol (PEG) and CK, and there were no difference in other growing development and physiological indexes.The plant height, tiller, root length, above ground fresh and dry biomass, underground fresh and dry biomass, root activity of Pennisetum setaceum'Rubrum'by treatment of 10% and 20% PEG decreased significantly than that by treatment of 5% PEG and CK.At the same time the chlorophyll content of 10%and 20%PEG reduced significantly, but the content of proline and MDA content increased significantly.Pennisetum setaceum'Rubrum'can still grow and develop normally, which was not wither.In summarize, Pennisetum setaceum'Rubrum'has strong drought resistance, which can endure drought stress to some degree.