In this paper, the convergence and stability conditions of extended DMC in the control of nonlinear SISO and MIMO systems are investigated. The formulations are based on the ordinary DMC in which, with successive linearization of the nonlinear model and new interpretation of disturbance, the nonlinear extension is deduced. In addition, new convergence and stability criteria are derived for SISO and MIMO systems. These criteria include convergence and stability in the case of longer control (M>1) and prediction (P>1) horizons, as well as the finite and infinite sampling time. Finally, the simulation results for a MIMO (3x3) model, based on a power unit nonlinear plant, are presented.