Seaweed particles were introduced to a bench-scale fluidized bed furnace to study the combustion of seaweed biomass (Enteromorpha clathrata). Quartz sand was used as the bed material. After dehydration and devolatilization, the E. clathrata char particle then burned according to the shrinking core conversion pattern. In order to identify key operating variables affecting seaweed combustion in fluidized bed. These operating variables (bed temperature, fluidization velocity and bed material height) were chosen as influential factors in this experiment. The mass ratio of the residual fixed carbon to parent fixed carbon was calculated to evaluate the influential factors. The grey relational analysis was used to study the degree of relative importance of the influential factors. Calculation results indicated that the influence of the bed height is the least, the bed temperature had the greatest influence. The experimental results and grey relational analysis can provide reference data for design of seaweed CFB furnaces. (C) 2012 Elsevier Ltd. All rights reserved.