Experiments regarding to biomass gasification using chemical looping (BGCL) were carried out in a fluidized bed reactor under argon atmosphere. Iron ore (natural hematite) was used as an oxygen carrier in the study. Similar to steam, a performance of oxygen carrier which provided oxygen source for biomass gasification by acting as a gasifying medium was found. An optimum Fe2O3/C molar ratio of 0.23 was determined with the aim of obtaining maximum gas yield of 1.06 Nm(3)/kg and gasification efficiency of 83.31%. The oxygen carrier was gradually deactivated with reduction time increasing, inhibiting the carbon and hydrogen in biomass from being converted into synthesis gas. The fraction of Fe2+ increased from 0 to 47.12% after reduction time of 45 min, which implied that active lattice oxygen of 49.75% was consumed. The oxygen carrier of fresh and reacted was analyzed by a series of characterization methods, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX). Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.