Abstract: There has been a study on a comparison of large fluctuation�s analysis in thin beams between two methods. These methods include sequential linear approximation and The modified Newton-Raphson analysis. These methods have been testet on a thin clamped long beam in finite elements model and the fluctuations of the beam changes made by the applied power to the tail are obtained. But out of this scope the sequential linear approximation method, despite having relatively good computational efficiency is less precise than Newton-Raphson method in terms of time and analysis stability.