Abstract: This study utilized simulation method,through the modeling of Rankine cycle,Kalinacycle and Uehara cycle,the differences in thermal efficiency（η）and leveled cost of energy（CLCOE）between different cycle processes were analyzed under different heat source temperature conditions. Meanwhile,the effects of evaporation temperature and turbine inlet pressure on thermal-economic performance in different cycle systems were also explored. The results show that Kalina cycle has highest thermal efficiency in each temperature condition of heat source,but its economic performance is poor. In low temperature heat source,the CLCOEof Rankine cycle with pure ammonia working fluid is the lowest under the same conditions. In design,Rankine cycle should choose saturated steam state,as far as possible to increase the turbine inlet pressure and reduce the evaporation superheat. Instead,in high temperature heat source,the CLCOEof Uehara cycle is the lowest. Moreover,there is a deviation of the turbine inlet pressure corresponding to the minimum CLCOE and the maximum thermal efficiency of Kalina cycle and Uehara cycle. Designed according to the minimum CLCOEprinciple at this point,more power generation and less equipment cost can be obtained. Therefore,thermal-economic performance of different cycles under different heat source temperature conditions should be considered in cycle flow design.