Abstract: By using vacuum bag molding process, T-shaped stiffened carbon fiber reinforced resin composite panel was prepared with CYCOM 5320-1 prepreg. Then the curing deformation was measured by laser tracer. The simulation of curing process of the panel with and without mold considered was launched by finite element method. The results of the simulation show that the simulation and test have the same deformation tendency, and the deformation fits well along the width direction. It is more close to the true values when considering the mold factor. It is because that before resin reaches gel point, the mold is heated and squeezes die cavity, which causes permanent deformation of the component.