Abstract: The dynamical characteristics of the restrained cantilever piping system constrained by a linear and torque spring at its free end are studied. The expression of vertical vibration mode-function of the restrained cantilever pipe system was derived from its boundary conditions based on the corresponding beam model. The equation of motion was discretized by Galerkin method. The natural characteristics and stability from non-conservative system to conservative system of this restrained cantilever pipe were analyzed by use of dynamical methods. The stimulation results shows that this special boundary piping system involves complicated dynamic characteristics. The supporting and constraining elastic coefficients have great effect on systematical natural frequency and stability, the systematical frequency varies with elastic coefficients, and instability way changes from flutter to divergence and influences other systematical parameters on dynamical characteristics of the piping system.