In this paper it is experimentally showed that the critical current de
nsity, J(C), at zero applied magnetic field in single phase (to better
than 5%) polycrystalline Y1Ba2Cu3O7-delta (YBCO) samples with distinc
t granular characteristics, depends inversely on the effective normal-
state resistance of the intergrain junctions. A way to predict J(C) fr
om the resistivity of the samples in the normal state is thus open.