As x increases from 0.05 to 0.10, the Curie temperature TC of polycrystalline perovskites La 0.80− x Ca 0.20 Sr x MnO 3 increases from 264 to 310K, near room temperature. The adiabatic temperature change ΔTad resulting from the magnetocaloric effect in these materials was measured directly. ΔTad reaches its peak around TC. Corresponding to x=0.05, 0.08, and 0.10, the maximum value of ΔTad of La 0.80− x Ca 0.20 Sr x MnO 3 induced by a magnetic field change of 1.92T was 1.33, 1.48, and 1.51K, respectively. ΔTad of La 0.80− x Ca 0.20 Sr x MnO 3 (x=0.05, 0.08, 0.10) induced by a magnetic field change of 1.79T is larger than 1K in a temperature range of about 10K. These results suggest that La 0.80− x Ca 0.20 Sr x MnO 3 is a potential material for magnetic refrigeration near room temperature.