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It is shown, that the possibility of a freezing of QCD running couplingconstant at zero in the approach with "forced analyticity" can not be in accordwith Schwinger-Dyson equation for gluon propagator. We propose to add to theanalytic expression the well-known infrared singular term $1/q^2$ as well aspole term corresponding to "excited gluon". With this example we formulate theprinciple of minimality of nonperturbative contributions in perturbative(ultraviolet) region, which allows us to fix ambiguities in introduction ofnonperturbative terms and maintain the finiteness of the gluon condensate. As aresult we obtain estimates of the gluon condensate, which quite agree withexisting data. The nonzero effective mass of the "excited gluon" leads also tosome interesting qualitative consequences.Comment: 11 pages, LATEX, 1 Table (calculation of gluon condensate corrected,  Table extended

ANALYTICITY AND MINIMALITY OF NONPERTURBATIVE CONTRIBUTIONS IN PERTURBATIVE REGION FOR $\bar \alpha_{{\lc s}}$