This study deals with computational fluid dynamics (CFD) analysis and optimization of a solar tower. The reason of making this study is to show velocity distribution in the solar tower and increase the average air velocity at inlet of turbine. To do this, CAD model of the solar tower has been drawn in 3D. Then the corresponding CAD model was solved numerically in commercial CFD code. Also slope of collector width, chimney diameter and height of tower are optimized to increase the average air velocity at inlet of turbine. As a result, it was found that change of corresponding geometries maximizes the efficiency of solar tower.