An electronic control unit (ECU) of a fuel injection control system of an internal combustion engine feedback-controls injection timing so that a cylinder pressure maximum value coincides with a target pressure value in an operation range, in which the cylinder pressure maximum value increases as ignition timing advances and torque increases as the ignition timing advances. The ECU feedback-controls the injection timing so that the ignition timing coincides with target timing in another operation range, in which the cylinder pressure maximum value increases as the ignition timing advances but the torque decreases as the ignition timing advances. Thus, the torque can be outputted efficiently by selecting the appropriate feedback control in accordance with the operation range.