Abstract: Taking the perennial ryegrass ‘Emerald’（Lolium perenne L.） as the test material, the pot experiment was conducted, the effects of the interaction of water-retaining agent and nitrogen, phosphorus and potassium fertilizer on the growth physiology of perennial ryegrass under drought stress were studied, in order to provide reference for the integrated regulation of water and fertilizer on turfgrass.The results showed that when the soil moisture was sufficient, the addition of water-retaining agent and the interaction of water-retaining agent and fertilizer had little effect on perennial ryegrass;when the soil moisture content was 55% of the maximum soil water holding capacity,25g·m^-2 water retention agent treatment without fertilization and 50g·m^-2 water retention agent interaction with nitrogen,phosphorus and potassium fertilizers under fertilization could promote perennial ryegrass growth.The increase in leaf surface area,leaf length,root surface area and total root length of perennial ryegrass,increased the relative water content and chlorophyll content of perennial ryegrass leaves,and reduced the relative electrical conductivity,malondialdehyde content and proline content of leaves.