A new constitutive model has been developed based on the homogenization method considering the micrcostructures of composites including both the mechanical and structural properties of fabric reinforcements. In particular, the current model aims to account for the effect of the fiber stiffness difference and orientation on anisotropy and also to simulate shear deformation without significant length change, as common in FRT(fabric reinforced thermoplastics) composite forming. For validation purposes, the model was implemented in an explicit dynamic finite element ocde and tested for pure shear. Using the new constitutive equation, the deformation behavior of woven fabric reinforced thermoplastic composites in hydroforming process was also analyzed.