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The statistical distributions of critical currents in series arrays of YBa2Cu3O7-x grain-boundary junctions have been studied by low-temperature laser scanning microscopy. A set of arrays has been fabricated on  NdGaO3 bicrystal substrates with misorientation angles from 2 × 10° up to 2 × 26° and patterned to the widths from 1.7 up to 5 micrometers. The critical current values of the individual junctions in the array have been obtained by focusing a laser beam on each junction and measuring the bias current at which the maximum laser-induced voltage response has appeared on the array. The measured critical current distributions have been demonstrated to be close to a log-normal Gauss function. A spread of this distribution has been found to increase with a bicrystal angle. YBa2Cu3O7-x grain-boundary topography has been studied by atomic force microscopy. From results of these measurements we suppose that the maximum values of critical current density might be assigned to the symmetrical facets of grain boundary.