An algorithm for aerodynamic preliminary design of axial compressors has been developed. The aerodynamic design modules are meanline design and annulus sizing, velocity triangle determination, blade design, and axial compressor three-dimensional geometry generator. The hub and tip radii are computed through the meanline method and the velocity triangles are determined through radial equilibrium and vortex equations. Using incidence and deviation angles correlations of NACA 65, DCA, and NACA 63-A4K6 pro les, the blades sections are designed on the compressor streamlines. The three-dimensional geometry of the designed compressors is the output of the developed preliminary design algorithm, which is generated through the developed geometrical code. This code generates the pro le coordinates of blades sections and stacks them over a guideline curve and assembles them on the compressor axis. In di erent sections of this article, the aforementioned modules are explained, the developed algorithm is presented, the required design variables are introduced, and the design constraints are investigated. Finally, the aero-dynamical and geometrical speci cations of the redesigned NACA 8-stage compressor achieved through the developed algorithm are presented and compared with the ones from original compressor.