Energetic polymers are useful as binders in rocket propellants and plastic bonded explosives to enhance the performance and to reduce the vulnerability of the system. In this paper the performance characteristics were calculated for two polymers based on heterocyclic monomers. The first polymer, glycidyl azide polymer (GAP), was prepared from polyepichlorohydrin (PECH), previously prepared from epichiorohydrin monomer, and sodium azide. The second one which is bis-azido-methyl 'oxetane polymer (BAMO) was prepared from 3,3-bis-(chloromethyl) oxetane monomer, with sodium azide. The performance characteristics of these polymers in mixtures with aluminium and ammonium perchlorate were calculated through a computer program. The specific impulse, adiabatic flame temperature were also calculated and discussed.