PURPOSE: To provide an internal combustion engine control system having improved operation feeling by preventing generation of hunting during the reduction process.

CONSTITUTION: An ECU30 is provided with a reduction process determining part 32 for suspending the operation of a reduction determining part 31 when an engine is determined to be in the reduction process. When tire engine is determined to be in the reduction process, the next reduction determination is not executed. Instead, the started reduction process is terminated.