The present invention provides a method for analyzing growth of void of resin in a porous material which comprising the steps of inputting data of the shape of a porous material filled with a resin material, and dividing the shape of the porous material into three-dimensional solid elements; inputting physical properties of the porous material, and boundary conditions including a pressure that is applied to the porous material; obtaining a resin-density distribution in the porous material through fluid analysis using a database obtained by experimentally measuring in advance a temporal change in a volume of gas generated from the resin material and porous material during heating, changes in a compressive force and compressive displacement respectively occurring when the porous material impregnated with the resin is compressed, and a change in a flow resistance of the resin; and comprehensively grasping production, growth, and distribution of voids deriving from gas generation.