The morphology of self-organized InP islands on GaInP buffer layers were probed by the whole island energy and surface energy. The island morphology was affected by Mismatch between GaxIn_(1-x)P buffer layer and InP island (MBI). With MBI increasing, the island elongates itself. The calculation also shows that the island metamorphosis was elongated with the increasing of the island volume. The morphology of different InP/GaxIn_(1-x)P systems, grown on GaAs substrate by metal organic chemical vapor deposition (MOCVD) method, was consistent with calculations. The self-organized islands at the surface of buffer layers were analyzed by scaling theories to show a periodical distribution. Buffer layers such as the mismatched GaInP on the GaAs (100) tilt to (111) 15 Celsius degree could improve the periodicity of the island separation distribution. The result also shows that the dislocations had different functions in island distribution along different directions, [110] and [1-10] directions.