In this paper, the atomic force constants of aluminum crystal determined by Brockhouse and Stewart from their data of inelastic one-phonon neut.ron scattering experiment are revised. The dispersion curves along 100 and 110 directions are calculated based on measurements of the intensity of the X-ray diffuse scattering. Furthermore, the calcuated specific heat at low temperature is in good agreement with the experimental data of Giauque and Meads after a correction for the electronic contribution is made.