In this paper, a modified version of PRML is discussed to reduce nonlinearity in digital high-density storage devices. We propose a PRML with a nonlinear compensator which can reduce nonlinear interaction between the stored flux regions on the storage channel, and apply it to recording channels with three different densities. By comparing its performance with the existing PRML through computer simulation, we confirm that the nonlinear intersymbol interference increasing with high-density recording channels can be reduced effectively by the PRML with a nonlinear compensator.