Due to the advantages of circulating fluidised bed application, circulating fluidised bed was used to gasify biomass in our laboratory and the preliminary results are presented here. Based on the preliminary results obtained, an improved gasification concept is proposed. In this concept, the riser is divided into several sections according to the sequences of reactions: i.e., devolatilisation (pyrolysis), gasification, cracking and combustion (oxidation). The focus of this concept is to isolate the devolatilisation and gasification processes from the combustion process. Based on this concept, the modelling has been developed inclusive of characteristic fluid-dynamics, kinetic chemical reactions, and mass and energy balance. The model can be expected to predict the overall performance of biomass-fuelled circulating fluidised-bed gasifier incorporating with the emissions release.