Abstract： The influences of quicklime, aluminite pastes and water in different contents on the dry density and compressive strength of autoclaved aerated blocks which are mainly made of fluidized bed combustion ashes (FBCA) are studied by experimental tests systematically. The experimental tests show that the content of quicklime is a primarily influencing factor, and it should not be under 17% when the large content of FBCA is used. The compressive strength of autoclaved aerated FBCA blocks is reduced obviously and the dry density has not been affected too much by the content of aluminite pastes. Besides, it should be noted that the content of aluminite pastes cannot exceed 0.08%. The content of water primarily influences the compressive strength of autoclaved aerated FBCA blocks when complying with the requirements of slurry consistence in blocks production.