Exhaust emission control system of internal combustion engine

An exhaust emission control system of an internal combustion engine having a fuel injection device that carries out main injection of fuel into cylinders of the internal combustion engine and then carries out sub injection of additional fuel in an expansion stroke, comprising:

• an exhaust emission control device that is disposed in an exhaust passage of the internal combustion engine and is capable of reducing harmful matters in exhaust;
• an operating state detecting device that is capable of detecting an operating state of the internal combustion engine;
• a target injection timing setting device that sets a target injection timing in the sub injection according to the operating state of the internal combustion engine;
• and
• a control device that provides control such that injection timing in the sub injection is set at a point earlier than the target injection timing when the sub injection is started, and the injection timing in the sub injection is then delayed to the target injection timing.