The anisotropy of the tensile strength of plain-weave fabric is numerically evaluated by the finite element simulations. The plain-weave fabrics show complicated deformation behavior that is quite different from that of the continuum. The mechanics of woven fabric is not sophisticated yet enough to evaluate the strength and fracture mechanism in arbitrary stress conditions. The opacity of the tensile strength significantly diminishes the material reliability for the advanced use of fabrics. This study addresses the ideal tensile strength in arbitrary directions by using the pseudo-continuum model, which we have proposed to predict the deformation behavior and fiber stresses of the plain-weave fabrics. In this study, the numerical simulations of uniaxial extension in various directions are carried out by one finite element subjected to ideally uniform deformation, and we predict the breaking loads and elongations corresponding to the ultimate strength of the fiber.