in a direct gasoline injection type spark igniting internal combustion engine provided with a turbocharger and a catalyst , in order to optimize an exhaust gas control , the structure is made such that an optimum exhaust gas control can be obtained only by one control valve by designing an arrangement of a pre catalyst , the turbocharger and a bypass exhaust gas passage and placing a control valve . further , a stratified operation area is expanded by reducing a capacity of the turbocharger , shifting an actuation area to a low capacity side and corresponding to an area of a stratified combustion so as to increase an air amount in the stratified area . accordingly , since it is possible to early warm up a main catalyst at a time of starting the engine , whereby the exhaust gas is purified , and the air amount in the stratified area is increased , the stratified area expands to a high output side and a fuel consumption is improved .