Fuel injection control system for in-cylinder injection internal combustion system

This invention relates to a fuel injection control system for an in-cylinder injection internal combustion engine. The system is provided with a fuel injection valve (1) arranged at a cylinder for injecting fuel into the cylinder, fuel feed pressure setting unit (121) for setting a fuel injection pressure of the fuel injection valve (1) at a low pressure in a specific operation state including a start-up of the internal combustion engine and for setting said fuel injection pressure at a high pressure in an operation state other than the specific operation state, and fuel injection controller (120) for setting an injection period of the fuel injection valve (1) as a period longer than a period of a single stroke in an operation cycle of the internal combustion engine in the specific operation state.