The knowledge of the mechanical behavior of woven fabrics is necessary in many applications, in particular, for the simulation of textile composite forming. However, in-plane shear behavior of textile performs is the most studied mechanical property, because this mode of deformation is necessary for forming on double curvature surfaces. In this paper, bias extension tests on non-crimp fabrics (NCF) have been conducted. Two different types of non-crimp fabrics were tested. Force and displacement were measured and then force displacement curves were plotted. Shear angles and normalized shear forces were determined. The shear stress was represented as function of the shear angle, and obtained curves were assigned polynomial regression equations. The derivative of those regression equations provides in-plane modulus of rigidity as a function of shear angle. The effect of small stitches on the rigidity of these fabrics was also examined.