Abstract: Applying nonlinear transformation, the simple method for calculating the coef-ficients of Normal Form by simple algebra has been derived. This method can also be used to solve nonlinear vibration problems. The process are as follows: first, to transform the original (equations to the standard first order differential equations discussed in this paper, then to find the solution of nonlinear vibration equation by simple algebra calculation. This method is easy to learn, and to use.