BaTi0.91Sn0.09O3 (BST) sample was prepared by the solid-state reaction method. The structural, morphological and electrocaloric properties were studied. The sample crystallized in the tetragonal structure with P4mm space group. Based on mapping image, the sensitivity and spatial resolution of the different elements in our sample were improved. According to the variation of polarization as function of temperature, our sample had a paraelectric-ferroelectric phase transition, around room temperature. The electrocaloric properties of our sample were investigated using theoretical approaches. The important parameters such as maximum entropy change, relative cooling power and full width at half maximum were explained qualitatively. These results make our sample promising candidate for refrigeration domain.