High-temperature X-ray diffraction and differential scanning calorimetry are used to study the features of structural changes in NdSr2Mn2O7+d complex oxide at temperatures from room to 1150 °C. Structural calculations by the Rietveld method establish a relationship between anomalies in the temperature dependences of unit cell parameters and in the DSC curves with changes in the lengths of bonds between Mn and Nd, Sr cations and oxygen atoms.