A steel-concrete composite wind power tower was proposed. And an automatic design program, which can design optimized section dimensions, was developed. If an outer diameter and requested capacities are given for a composite wind power tower, the developed program performs axial force-bending moment interaction analyses for hundreds of sections of the tower and suggests ten optimized designs. The analysis considers material nonlinearities of concrete and steel, and the confining effect of concrete. As the analysis examples, some sections were designed for arbitrarily given moments and axial forces. And a designing process was performed for the loads of wind power turbine and wind load. The designed section and analysis results showed the developed program suggested rational and satisfactory section designs.tower, the developed program erforms axial force-bending moment interaction analyses for hundreds of sections of the tower and suggests ten optimized designs. The analysis considers material nonlinearities of concrete and steel, and the confining effect of concrete. As the analysis examples, some sections were designed for arbitrarily given moments and axial forces. And a designing process was performed for the loads of wind power turbine and wind load. The designed section and analysis results showed the developed program suggested rational and satisfactory section designs.