The stabilty of Model Predictive Control (MPC) for the SISO system is analyzed without restricting the function of MPC to one-step prediction. Some stability theorems are newly derived. They assure that a stable MPC system is easily realized simply by tuning a couple of control parameters even if large plant-model mismatch exists. A guideline for the tuning control parameters is also proposed. © 1990, The Society of Chemical Engineers, Japan. All rights reserved.