A dynamic simulation of fiber reinforced composite materials mold filling process with double inlets is presented based on the gas-solid-liquid model proposed by Yang et al. [B.X. Yang, J. Ouyang, J. Tao, CT. Liu, Modeling and simulation of fiber reinforced polymer mold filling process by level set method, CMES - Computer Modeling in Engineering and Sciences 63 (3) (2010) 191-222]. Numerical results show that the fibers far away from the melt interface are in skin-core-skin structure, while those near the interface are almost parallel to the arc of the interface. When the two streams of melts meet, the weld line will be formed, where the orientation of fibers is perpendicular to the flow direction. The orientation of fibers of the numerical result shows well agreement with the experimental results. Finally, the mechanical properties of fiber reinforced composite materials are analyzed. The composite materials with skin-core-skin structure are regarded as laminated orthogonal plywood and the elastic modulus, the shear modulus and Poisson's ratio are predicted under different slenderness ratios and fiber volume fractions. (C) 2011 Elsevier B.V. All rights reserved.