The status of the single point electronic fuel injection system technologies are overviewed. The major technological features of the systems which have teen announced or introduced in the market are compared. The merits and the demerits of the various system designs and the components, such as injector position, fuel system pressure, injection nozzle design and sensors are described. The possibilities to improve the air fuel distribution from cylinder to cylinder, the transient response of the engine in the acceleration mode and the stability of the engine revolution during idle with sophisticated control algorythm are demonstrated. The learning control is also very useful to compensate the deterioration of the system or the offset of the control point. In conclusion, comparing with multi point injection and carburetor, the single point injection system will take the major position of the fuel supply system for spark ignition engine, though the multi point injection system and the carburetor system still keep their position as a high performance component and a low cost component.