An engine control apparatus which may be employed in automotive vehicles. The engine control apparatus is equipped with a controlled variable arithmetic expression which defines correlations between a plurality of combustion parameters and a plurality of controlled variables of actuators for control of an operation of the engine to calculate a combination of command values to be outputted to the actuators for regulating the controlled variables needed to achieve target values of the combustion parameters. When one of the command values is produced outside an allowable operation range of a corresponding one of the actuators, the engine control apparatus corrects or limits the one of the command values to an upper or a lower limit of the allowable operation range, thereby ensuring the stability in bringing engine output characteristics close to desired values.