For an in-cylinder direct injection spark ignition internal combustion engine including an intake port provided with a tumble control valve, a startup control method is presented. When a startup of the engine satisfies a predetermined cold start condition requiring a retard operation of the engine for catalyst warmup, a startup process is performed. The startup process includes: closing the tumble control valve; after the closing of the tumble control valve, starting to crank the engine; implementing fuel injection of the engine by a single-injection operation during a time period from an initial cycle of combustion of the engine to an event that the engine rises and reaches a predetermined rotation speed; after the event, shifting from the single-injection operation to a multiple-injection operation; and substantially simultaneously with the shifting to the multiple-injection operation, starting an ignition timing retard.
