The purpose of this study was to determine the effect of temperature on growth and phenolic acids on pangolagrass A254 (Digitaria decumbens Stents.) and delhigrass A70 (Dichanthium annulatum (Forsk.) Stapt). High day/night temperature (30/25°C) improved the growth of both grasses while low temperature (20/15°C) retarded the growth of delhigrass A70. High temperature decreased crude protein but increased neutral and acid detergent fiber content of grasses. Both high and low temperatures increased phenolic acid contents of stem and root, especially for p-coumaric acid.