The technology of hydrogen generation from biomass has attracted more and more attentions nowadays. In this work, three biomass-based chemical looping hydrogen generation systems, Systems A, B and C, are comprehensively studied. System A is mainly composed of biomass hydrogasification, methane reformation and the calcium-looping based CO2 absorption. System B is mainly composed of biomass steam gasification and Fe2O3/FeO-looping based hydrogen generation circulation. System C is mainly composed of biomass steam gasification and Fe3O4/FeO-looping based hydrogen generation circulation. The three systems are modeled and their characteristics are analyzed and compared thermodynamically. System A has the highest cold gas efficiency (CGE) which is 72%; System B has the lowest CGE of 54% but it can generate additional nitrogen as byproduct; System C has the highest hydrogen generation ratio and its CGE is moderate and is 60%. The carbon dioxide sequestration rates of the three systems are all above 90%. Copyrightc (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.