The design and development of structure models based on dynamic parameters are of priority importance in airframe design. Limitations on natural vibration frequencies arise from the need to tune away from undesirable vibrations caused, for example, by engine vibration, propeller rotation, aeroelastic phenomena, etc. In this paper we discuss the design of structures on the basis of dynamic characteristics such as natural vibration frequencies. Two methods are submitted for the design of structure models from natural frequencies with sensitivity analysis of two groups of design parameters: material-distribution and frame-shape parameters.