Abstract: Because of the high energy consumption rates as well as creating a clean environment, we need a fuel which can be substituted for fossil fuels. Natural Gas (CNG) and Hydrogen (H ) are the best among the 2 alternative fuels and possess specific characteristics such as sustainability, renewability and clean burning capacity. This review study is presented of contemporary research and given a comprehensive overview on the HCNG fueled diesel engine. Major subjects that have discussed here include introduction and fundamentals of dual fuel diesel engine with using natural gas and hydrogen and details on the different mixture formation strategies of HCNG fueled and their effects on engine performance and emissions characteristics.