The conventional dynamic vibration absorber is very efficient in inhibiting the vibration of a machine. This is accomplished by "tuning" the absorber to the frequency of the harmonic disturbing force. If, however, the frequency of the disturbing force varies over a tuning frequency range in the normal operation of the system, the linear dynamic absorber may become inoperative and might aggravate matters particularly. This study is to endow the dynamic absorber with greater flexibility in suppressing vibrations throught a range of frequencies of the disturbing force. By introducing springs with nonlinear characteristics into its design, the results can be obtained. In this paper, the machine and the absorber were modelled as a nonlinear two-degree-of freedom system. And the concepts of nonlinear normal mode were adopted to obtain this purpose.s purpose.