Chemical looping gasification is a promising technology to convert biomass into syngas with low adverse effects by heat loss and production dilution. This study utilized 60% loading Fe2O3/Al2O3 oxygen carrier (OC) for gasification tests on four biomass samples: rice straw, corn stalk, peanut shell and wheat straw under OC/ biomass (OC/B) ratio of 1.0, steam/biomass (S/B) ratio of 2.8, reaction time of 20 min, and reaction temperature of 850 degrees C. All biomass samples yielded similar gasification performances: CO content 19.2-23.1%, H-2 content 36.5-41.1%, carbon conversion rate 72.3-82.2% and gas yield 0.78-1.04 L/g. The gasification performance using rice straw was optimized on maximum H-2/CO ratio using three levels Box-Behnken experimental design: 899.6 degrees C, 20.3 min, OC/B = 1.02 and S/B = 2.89, leading to maximum H-2/CO value of 2.20. Verification tests confirmed this prediction. The adopted Fe-based OC can be applied to generate syngas from the tested biomass with promising outcomes.