La1-xSrxMnO3 (LSMO) compounds (0.175 <= x <= 0.30) were prepared by conventional solid-state reaction method. Temperature dependence of the total hemispherical emittance (epsilon(H)) of the compounds from 173 to 373 K was measured on a calorimetric emissometer (CE) which was constructed based on the steady-state calorimetric method. The compounds show thermochromic properties and epsilon(H)'s have low value at low temperature and have high value at high temperature, because the compounds are dominated by metallic phase and insulator phase, respectively. We use the phase separation model to interpret the temperature dependence Of epsilon(H). (C) 2008 Elsevier B.V. All rights reserved.