[en] Two methods of a search for resonance characteristics in scattering and reactions in the framework of an oscillator n representation are considered. The first method consists in finding complex poles of the S matrix. Taking as example a simple separable potential it is shown that scatterinq theory equations in n representation really permit to find the position and widths of resonances related to such poles. It is shown as well that the scattering theory in n representation has much in common with the usual scattering theory in coordinate representation. In fact, each notion of the usual scattering theory has its discrete analog in n space. In particular, in the paper disctrete Panalog of the Jaffe-Low matrix is introduced and in approximatio isolated resonance Breit-Wigner formulas for amplitude of scattering and reaction are obtained. In the above approximation partial widths and energies of resonances are most simply related to poles and residues of the p matrix obtained as a result of standard diagonalized calculations