Abstract: A novel biomass-fired organic Rankine cycle（ORC）combined with heat and power（CHP）system is developed,in which the supplying heating ratio is defined to characterize the energy distribution relationship between the supplying heat system and ORC.System parameters are optimized through thermodynamic analysis and economic assessment. Results show that the temperature of pressurized hot water generated from biomass boiler is improved with increasing evaporation temperature. The biomass-fired ORC-CHP system achieves higher supplying heating ratio,exergy efficiency and thermal efficiency with higher temperature of supplying heat hot water,while presenting lower power efficiency,primary energy saving ratio and system total investment,in which the optimized evaporation temperature considering dynamic payback period and profit ratio of investment（PRI）is lower than the counterpart achieved by net present value. The primary energy saving ratio（PESR）of cogeneration system varies from 5.91%-12.78%,while the PRI changing between 3.25 and 3.88. As a result,the studied bioenergy system is thermodynamically feasible and economically attractive.