Nondestructive testing of the strength of materials and structures is based on the evaluation of representative strength indices that allow forecasting of the instant that destruction will occur. Flaws in a material and complexities in a structure lead to nonuniformities in their structural, stressed-strained, and strength states, to the reduction of the testability of objects, and the necessity of increasing their strength margin. The criteria for determining the kind and nonuniformity of the strength state of structural materials are formulated, a technique for qualitative evaluation of the degree of the strength nonuniformity is considered, and the correlations of different acoustic-emission and geometric strength characteristics, which were obtained by a nondestructive method, are compared to the durability of specimens.