It is well established from studies of bicrystals that the wetting behavior of grain boundary (GB) depends on the GB crystallography and stress. However, only in several researches of polycrystalline materials properties this boundary-boundary variability is taken into account. In polycrystalline materials the whole network of GB is never completely wetted. The number of wetted boundaries and the topology of their network vary as a function of many factors such as texture, intensity and sign of residual or applied stresses, impurities, content, and specimen size. The role of these factors is not clearly understood yet. This article is devoted to the effect of material structure and stresses on the relative number of wetted GBs and on the connectivity of intergranular liquid in polycrystalline materials. Percolation approach is employed to describe the liquid phase connectivity in internal wetted polycrystals. Some examples are regarded. The relative number of wetted GBs in Zn/Ga system is established on the basis of the distribution of GB orientations and GB wetting statistics. The influence of stresses on the network topology and percolation threshold (the critical concentration of wetted boundaries at which an infinite network appears) value is discussed. The computer modeling is fulfilled to evaluate the threshold as the function of grain shape. The topology of liquid phase inclusions is discussed in terms of critical indexes.