Abstract
In this research a new algorithem has been applied to calculate the phonon images for orthohombic crystals, this method depend on the calculation of the phonon imaging from the phase velocity and slowness surface only without the detail calculation the group velocity, this has been done by determining the directions of the group velocity from the slowness surface. The Monte Carlo method has been used to generate the wave vectors in reduced Brilluon zone, then transformed these vectors to slowness surface space and the unit vectors of group velocity are determind. A comparision between the new and classical algorithem results has been done for the calculation of the phonon images for orthohombic crystals, the results shows a good agrement between the new and the classical algorithem.