PURPOSE: To make fuel injection timing optimum in accord with the property of fuel used for a fuel injection timing control device of an internal combustion engine.

CONSTITUTION: When an internal combustion engine is detected to be in the condition of being not at starting (step 100), already begun into execution of independent injection (step 110), and in the steady operation, a characteristic value KFUEL showing fuel property is computed based on the air-fuel ratio characteristic at acceleration/deceleration (step 120). Based on the computed KFUEL, fuel injection timing is corrected to more advance so as to sufficiently insure a carburetion time after injection as the fuel is heavier (step 130), and the fuel is injected (step 140).