Compression self-ignition gasoline engine

A compression self-ignition gasoline engine includes a stratifying device stratifying gas in a combustion chamber of the engine, a fuel injector directly injecting fuel in the combustion chamber and a controller connected to the stratifying device and the fuel injector. The controller controlling the stratifying device to produce a high temperature gas layer of a high temperature gas and a low temperature gas layer of a low temperature gas in the combustion chamber. The controller further controls the fuel injector to inject the fuel to both the high temperature gas layer and the low temperature gas layer.