The nozzle of the fuel injector for the Gasoline Direct Injection(GDI)engine exposing to high temperature combustion gas and soot makes it easier for deposits to accumulate on.Deposit formation in the injector orifice can both restrict the fuel flow and alter the spray characteristics of the injectors and high levels of flow restriction and any level of spray distortion cannot be adequately controlled electronically.The decrease of the fuel flow rate results in the decrease of power and the fuel spray pattern distortion impacts combustion quality,which can lead to loss in power and fuel economy,as well as increased exhaust emissions.The present paper experimentally investigates the effects of deposits on spray behaviors of a six-hole GDI injector.The flow rate,spray angle,penetration distance and the particle sizes of the sprays of several new GDI injectors at different injection pressure are compared with these of the injectors covered by deposits that have been used in a vehicle for 58 thousand kilometers.The results show that the flow rates of the used injectors decrease by about 10%,the spray angles enlarge a little,and the penetration distance slightly decreases.It is predicted that the deposits do have influenced the power and economy of the engine and it will be more and more critical as the deposits grow with the engine running.