To suppress misfire or smoke generation by determining the correction factor for the fuel injection amount control value through grasping of the actual fuel injection amount while internal-combustion engine is in the regular operating condition as specified, and enhancing the air-fuel ratio controlling accuracy in the stratified combustion.

When the fuel pressure PR having attained the value PR0 during the fuel cut and stabilized decreases to PR1 during the minimum valve opening time injection Δt after the fuel cut, the fuel pressure drop ΔP (=PR0-PR1) is an amount accurately reflecting the actual fuel injection amount. The value ΔP/Δt will represent the total flow rate characteristic of the injector group, and a great ΔP/Δt signifies that the rate of injection is large. The factor for correcting the fuel injection amount controlling value is determined from ΔP/Δt.