Abstract: In order to eliminate the bubble during the autoclave curing of composites , the shape changing processof bubbles during t raversing through the monolayer fabric was studied preliminarily , and the driving force for themoving of bubbles was described based on the pressure. The effect s of the viscosity of resin , the size of the bubble ,the external pressure , the inter-space area as well as the number of layers on the t raversing behavior of bubbles werealso studied. The result s show that bubble t raverses through the layers by the flow of resin ; for a single void , thelower the viscosity of the resin is , the less the layers are , the larger the inter-space size is and the easier it is for thebubble to t raverse through the layers. Under the same condition it is easier for a large bubble to t raverse through thelayers than for a small one. These result s will provide the basis for establishing the bubble movement model in thehot-compaction process.