In this paper, the crystal structure of Pr(Sr0.2Ca0.8)2Mn2O7 double-layered manganite and the effect of low temperatures have been studied by X-ray diffraction method. It is found that this compound crystallizes into Cmc21 non-centrosymmetric spatial group. The crystal structure at room temperature is compared with that at low temperatures. Lowering the temperature not only leads to a change in the bond lengths, but also causes differences in the bond itself, namely, a change in angles.