Vibrational contribution to heat capacity of solid is explained. The Debye model is introduced through semi-classical consideration. It is emphasized that the Debye model does not assume the isotropy of solid. Lattice dynamical calculation of phonon density of states is described within a harmonic approximation for a 1-dimensional crystal in detail. Application to molecular solids is outlined while assuming the use of the atom-atom potential method. Some examples are described of utilization of lattice dynamical calculation and of analysis of lattice heat capacity. Briefly commented are advanced topics of lattice heat capacity, including localization of vibration and low-energy excitation in disordered system, anharmonic cases, and phason contribution in incommensurately modulated system.