This study investigated the effects of calcium based catalyst (calcium oxide) on variation of gas composition in catalytic gasification reaction stages by controlling the gasification temperature between 600 degrees C and 900 degrees C whilst varying a catalyst/biomass ratio from 0 to 0.2 w/w. The tested biomass generated from used bamboo chopsticks were used as the feedstock. To assess the gas composition variation, the ratio of H-2/CO, H-2/CO2, CO/CO2, and 3H(2)/CH4 are four important factors that affect the performance of catalytic gasification process. The maximum ratio of H-2/CO increased from 0.23 to 0.72 in the gasification temperature range between 600 degrees C and 900 degrees C and 0%-20% calcium based catalyst addition ratio. This is due to enhanced H-2 production as a result of the facilitated water-gas shift reaction. The ratios of CO/CO2 and 3H(2)/CH4 increased significantly from 0.9 to 2.1 and from 2.6 to 4.1, respectively, when the gasification temperature increased from 600 degrees C to 900 degrees C and 20% catalyst addition ratio. Obviously, the high temperature and catalyst addition are favorable for production of CO and H-2 during gasification of tested biomass. In conclusion, the tested mineral calcium based catalyst (CaO) can help facilitating the reaction rate of partial oxidation and water gas shift reaction, enhancing the quality of synthesis gas, and reduction of the gasification reaction time. This catalyst has potential application in gasification of waste bamboo chopsticks in the future. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.