Understanding the mechanical properties of carbon fiber reinforcements is necessary for the simulation of forming processes. A unit-cell mesoscopic model provides a tool to implement virtual material characterizations which can be served as an input for macroscopic modelling, avoiding complex experimental tests and significantly reducing calculation time. Meanwhile, the occurrence of some local defects during the forming process, such as the gapping, would be easier to be detected through a mesoscopic approach. In this research, a novel mesoscale model for biaxial non-crimp fabric is developed based on the geometry measured from the results of X-ray tomography. A hyperelastic constitutive law is applied to the fiber yarns which are considered as a continuous medium. One type of unit-cell model is chosen and validated through a comparison with experimental tests and its in-plane shear behavior is studied.