Аннотация:The structure-property correlation establishing is considered, when the topological indices (TI) are used for numerical representation of the molecule’s structure. A simple mathematical expression is suggested, which allow calculating the precise superior boundary for square correlation coefficient value R2 (informativity) for any possible relations between some characteristic and the chosen TI. With determined R2 it is possible to estimate quantitatively TI applicability for any characteristic, i.e. calculate the maximum attainable R2 for all possible representations of the considered characteristic as TI function.