The large quantity of pollutants,including primerily hydrogen chloride and other propellant combustion products like dioxine and some carcinogens from rocket exhaust,are a serious threat to the atmosphere in which the humankind live,In this paper some ways to develop chlorine- and fluorine-free solid propellants and the new type of oxidizers with superior properties are discussed.From the viewpoint of putting the energy,chemical stability and combustion regularity in the important place,the author proposes that ammonium nitrate,hydrazine nitrate,ammonium dinitramide and hydrazine nitroform would be suitable oxidizers to substitute ammomium perchlorate and HMX in solid propellants.The thermodynamic calculation for some model formulations were made and compared width those of some conventional propellants.The results obtained therefrom may be taken as a basis to develop the ecologically safe propellant.