Abstract: We compared the light-response curves of two strains of Eremochloa ophiuroides, the Yaan and the Common strains from different origins, to determine if the two strains exhibit different tolerances to drought stress. Three watering regimes were designed: well-watered (80% of field water capacity, FWC), moderate drought (50% FWC) and intense drought (35% FWC) all applied for one growing season. Net photosynthetic rate and stomatal conductance increased with increases of light intensity, while both significantly decreased when exposed to drought stress. The maximum assimilation rate (A_max) at saturation photosynthetic photon flux density (PPFD) and light saturation point (LSP) of Common were significantly reduced by drought. A_max decreased from 22.3 to 11.2 μmol/(m²·s) as the LSP dropped from 578 to 350 μmol/(m²·s), while for Yaan, the A_max decreased from 24.5 to 13.0 μmol/(m²·s) as the LSP decreased from 694 to 474 μmol/(m²·s). In addition, the net photosynthetic rate of the Yaan strain was much higher than that of the Common strain at the same light intensity. Based on the differences in light-response curves, it was concluded that the Yaan strain had stronger drought tolerance and a greater capacity to use light than Common, which was introduced from America.