A preliminary study is presented to realize an idea to optimize the shape of an airfoil section in accordance with airplane flight conditions, deforming it elastically by internal pressure control. Here is calculated by analytical method rather than by finite element method the shape of an airfoil section after deformed largely as an elastic thin shell by applying internal pressure. In the analysis are treated the two types of airfoil sections; a symmetric airfoil section and a cambered airfoil section. In the former case, the good agreement is obtained between the analytical results and the experimental results. Moreover, it is confirmed that this method can be applied to any cylindrical shells with a uniform section besides airfoil sections, if the ordinate of the initial shape is expressed in a polynomial of the abscissa.