Abstract: On the basis of the method proposed in[1]. the paper gives the method for finding thenormal form of nonsemi-simple bifurcation problems. As an example, it analyses thenormal form of a general nonlinear dynamical system with the nonsemi-simple double zeroeigenvalues, and gives out the expression for the coefficients in the normal form by usingthose in the original system.

Key words: normal form, nonsemi-simple bifurcation