This paper presents a new tridimensional approach for transonic fan blade design. The proposed parameterization uses parameters closely linked to aerodynamic performance of blades, such as beta angles and thickness distributions and allows the control of these parameters in both axial and spans wise directions independently. In addition, a multi-level modification approach is presented, which allows modifying the blade geometry locally or globally. This multi-level approach enables to use a reduced number of parameters for preliminary design optimizations and to switch, in a seamless way, to higher precision for final design optimizations. The parameterization is validated by the replication and modification of the NASA Rotor 67 and examples are given of the application of the parameterization to multidisciplinary fan blade design.