This paper describes about the green engine, which is one of the most interesting discoveries of the new millennium. It has got some unique features when compared to other contemporary engines. This engine is one of the pistonless with features like high expansion ratio, strong swirling, sequential variable compression ratio, direct intake etc. The efficiency of this engine is very high and also the exhaust emissions are near zero. The significance of the engine lies in the efficiency when the present world is facing some serious problems regarding energy crisis. Various researches on this engine is being carried out and yet to find the demerits of this engine. Generators have been produced by using green engine. Hence the GREEN ENGINE is the ENGINE OF FUTURE. There are many disadvantages of conventional engine one of which pollution The efficiency of this engine is high when compared to the contemporary engine and also the exhaust emission are near zero. The significance of the engine lies in the efficiency when the present word condition of limited resource of energy are considered. Prototype of the engine has been developed.