PURPOSE: To facilitate variation of the number of operating cylinders by a method wherein the content of a shift register is shifted by a crank angle signal showing a piston of whichever cylinder has come to a predetermined position before the upper dead point of compression and the fuel injection is effected based on the data thereof.

CONSTITUTION: The bases of power transistors 19aW19f driving injection valves 2W7 are connected to the output terminal of a six bits data latch circuit 24 (not shown) through the output terminal of a flip-flop 18 and a diode. The data of the data latch circuit 24 is determined by latching the data of the six bits shift register 25 upon beginning of the injection. The last stage output of the shift register 25 (not shown) is inputted into the J terminal thereof and shifts the data upon every time whereat the 120° signal (b) of a crank angle sensor 9 is inputted into a clock terminal. On the other hand, a microcomputer 14 operates the pulse width of fuel injection and switches the set value of the latch circuit 26 (not shown).