Empirical interatomic potential parameters are determined for group semiconductors such as CdS, CdSe, ZnS, and ZnSe. The structural properties of zinc-blende CdS, CdSe, ZnS, and ZnSe are calculated. A good agreement between the calculated and experimental values of the lattice constant, the cohesion energy, and bulk modulus and its derivative are obtained. The versality of these empirical potential parameters is confirmed by the calculation of elastic constants for CdS, CdSe, ZnS, and ZnSe. We have used the molecular-dynamics methods for the calculations of the thermal expansion and heat capacity. The results compare well with available results.