A novel chemical looping power generation system is presented based on the biomass-coal co-gasification with steam. The effects of different key operation parameters including biomass mass fraction (R-b), steam to carbon mole ratio (R-sc), gasification temperature (T-g) and iron to fuel mole ratio (R-if) on the system performances like energy efficiency (eta(e)), total energy efficiency (eta(te)), exergy efficiency (eta(ex)), total exergy efficiency (eta(tex)) and carbon capture rate (eta(cc)) are analyzed. A benchmark condition is set, under which eta(te), eta(tex) and eta(cc) are found to be 39.9%, 37.6% and 96.0%, respectively. Furthermore, detailed energy Sankey diagram and exergy Grassmann diagram are drawn for the entire system operating under the benchmark condition. The energy and exergy efficiencies of the units composing the system are also predicted. (C) 2016 Elsevier Ltd. All rights reserved.