Аннотация:Within the Usadel equations the proximity effect al the boundary between two superconducting metals is analyzed, the thickness d of one S' of metals being supposed smaller significantly than its coherence length xi*. By the numerical methods the density of states at SS'-boundary, gap DELTA(g) in the elementary excitation spectrum, and values of the order parameter DELTA(s), DELTA(h) in S and S' superconductors are calculated, The temperatury dependences of these values are shown to be determined by the suppression parameter gamma(M) = (rho(s)xi(s)*d)/(rhoxi*2) and the ratio of the critical temperatures T(c)*/T(c), in the general case the dependences not coinciding with each other. The results obtained are used for calculating the temperature dependences of critical currents and V-1 characteristics of tunneling SS'IS'S junctions with large capacity. The character of changing these characteristcs is traced with the variation of parameter gamma(M) and ratio T(c)*/T(c),. It is shown that for the NbN/Nb/Al/AlO(x)/Al/Nb/NbN structures in the helium temperature range and near T(c) the critical current value bay be 90% and 30% from the maximum possible one, respectively. The study of features of V-I characteristics may give an additional information on the properties of Nb/Al boundary.