The La 0.8 Ca 0.2−x □ x MnO 3 , (x=0–0.20) compounds were prepared by the solid-state reaction. X-ray diffraction (XRD) and magnetic measurements were used to investigate the calcium-vacancy effect on the physical properties. The XRD data have been analyzed by Rietveld refinement technique. Samples with x=0, 0.05 and 0.10 are found to be single phase and crystallize in orthorhombic symmetry with Pnma space group. Moreover, for x=0.15 and 0.20 samples, the refinement has revealed the coexistence of both Pnma orthorhombic and R3¯c rhombohedral phases. The magnetic study has showed that the magnetization exhibits maximum at x=0.15 and minimum at x=0.2. Such behavior was interpreted in terms of orthorhombic distortion contribution, which is related to the orthorhombic structure, leading to magnetization decrease. In addition, maximum magnetic entropy change (ΔS M ) for x=0 sample was found to reach ∼4.1J/kgK under an applied magnetic field of 5T, which is very sufficient for potential application in magnetic refrigeration. For the same applied magnetic field (μ 0 H=5T), the Relative Cooling Power (RCP) values are found to vary between 270 and 300J/kg. As consequence, the La 0.8 Ca 0.2−x □ x MnO 3 compounds can be used as a composite for magnetic refrigeration in the [175–183] K temperature range.