A fuel injection control system of low cost for a cylinder injection type internal combustion engine, which system is capable of preventing degradation of fuel injection quantity accuracy which may be brought about by disturbances such as change of a battery voltage, change of resistance of a plunger coil of the fuel injection valve (1) and change of the fuel pressure (Fp) acting on the fuel injection valve (1) which may occur in the course of overexcitation driving of the fuel injection valve (1) at a battery voltage, to thereby allow the fuel injection quantity control to be secured for the fuel injection valve (1) over an extended range. The fuel injection control system includes an overexcitation drive means (2) for outputting a overexcitation current to the fuel injection valve (1) at a battery voltage, a holding drive means (3) for outputting a holding current smaller than the overexcitation current for holding the fuel injection valve (1) in a valve open state, a fuel injection valve control means (4) for changing over output operation of the overexcitation drive means (2) with output operation of the holding drive means (3) to thereby control driving operation for the fuel injection valve (1), and a switching time-point change means (6) for changing a time point for switching the output operation of the overexcitation drive means (2) to the output operation of the holding drive means (3).