Abstract: A numerical optimization method is presented for aerodynamic design of propeller.As the basis of optimization,the strip theory based on Goldstein theory is applied to prediction of the propeller aerodynamic performance.The comparison of calculated results with experimental data shows that,the strip theory is appropriate to the optimization.The mixed penalty function method is used for the optimization.By the means of the method presented here,two propellers have been designed and redesigned under identical flight conditions.The calculated results indicate that the variation of efficiency with geometry parameters is more gradual in the vicinity of efficiency maximum.It is also shown,if both chords and twists in different sections are taken as design variables,the blade of the optimized propeller would be more narrow than that if only the twists are taken as design variables.Therefore the optimized propeller would be lighter and more efficient at cruise conditions.