<p>A mechanism of crack stopping by weak fiber-matrix interface in unidirectional composite is specified. The asymptotic analysis of stress state near the elongated elliptical hole in orthotropic plate has shown that splitting at this hole occurs mainly due to shear stresses along the fibers. These shear stresses reach the highest value at the hole contour and depend weakly on the degree of material elastic properties anisotropy. Analyzing the highest values of stresses near the hole, it is possible to estimate the appropriate material characteristics for the crack stopping mechanism realization. The role of the remaining after splitting notch was considered. It was obtained that the real stress concentration factor at hole in unidirectional composites after splitting is not higher than 2. This value occurs near the remaining shallow notch and is several times lower, than the regular theoretical stress concentration factor in plate near circular or elliptical hole, determined numerically or analytically.</p>