In this work, the characteristic basis function method (CBFM) is presented in junction with the characteristic modes (CMs). In this approach, characteristic modes are defined as primary basis functions on each array element. In order to take into account mutual couplings, secondary basis functions are introduced as in the conventional CBFM. Since characteristic modes are independent of the excitation, the reduced matrix can be constructed without the information of the excitation by using characteristic modes as primary basis functions. Once the reduced matrix is calculated and stored, it can be reused in the array problem for different type of excitations.