We developed a mesh morphing technique, which can be used to change the shape of existing analytical mesh models, and generated a mesh model for a new shape by morphing the mesh model for the previous one. Therefore, our method is suitable to use for analysis during the early stage of design because it reduces the amount of time required to generate analytical mesh models. However, this technique is impossible to morph a free-form surface, and to change surface type. Accordingly, we developed the fitting morphing technique for solving the problem. This technique is possible to morph based on specification of the STL data as morphed shapes and indication of fitting nodes and movable nodes. We developed a series of techniques that include three distinct features. (1) Geometric feature recognition algorithm based on region growing method. (2) Geometric feature assignment algorithm on the basis of distance and angle of geometric features between original mesh and morphed shapes. (3) Node fitting and moving algorithm by displacement coefficient calculation using Ferguson curve characteristics. We confirmed that this technique can morphed to free-form surface from cylindrical surface by applying to the piston head model. Furthermore, the technique can morphed to maintain the boundary continuity of the shape by applying to the gear model.