Hydrogen production from model bio-syngas with high content of CO2 through water-gas shift reaction (WGSR) was investigated by a fixed-bed reactor. The model bio-syngas was determined from actual biomass gasification system. To enhance the yield of hydrogen, the Fe-Cr and Cu-Zn commercial catalysts were tested respectively under the presence of 0-30 vol.% and 37 vol.% CO2. The impacts of space velocity, reaction temperature, and H2O/CO ratio were investigated. Under high CO2 concentration, Fe-Cr and Cu-Zn catalysts were proved suitable for bio-syngas WGSR. The relatively improving efficiency (RIE) suggests that reactant gas with more than 20% CO2 favors space velocity lower than 2500 h(-1). The extreme value of H-2 increase is observed at consistent 450 degrees C, which is not affected by the increase of CO2. By lowering the space velocity of WGSR, the CO outlet can reach as low as 0.63 vol.% (6300 ppm), and 90.73% CO conversion is accomplished even with 37 vol.% CO2. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.