In present manuscript phonon dynamics of alkaline-earth oxides, MgO by including the three-body interconnections in the framework of ‘van der Waals three-body force shell model’ (VTBFSM) is based on my thorough theoretical study of the relevant research papers on this topic. The studies of lattice energy and other properties made by Huggins and Sakamoto [1] .The instigate work of Kellerman [2] for lattice dynamics of the alkali halides has provided attentive theoretically as well as experimentally. The thermal properties, densities of states (DOS), structure analysis, direction-dependent ultrasonic velocities and Debye velocity of magnesium oxide have been evaluated in present investigation. However, a considerable improvement in computational results has been obtained by the use of the present model and successfully predicted the lattice dynamic of MgO for the study of bulk thermo-elastic properties. The results of this investigation are discussed successfully with available experimental data