Abstarct: This research wants to improve the quality of polyurethane-baxsed conductive adhesives and fillers for spherical copper and silver powder, flake copper and silver powder, graphite and carbon nanotubes. The effect of filler shape (spherical, flaky and tubular) on the electrical conductivity of the adhesive has been investigated. In this research, using a ball mill, in both wet and dry states, spherical copper and silver powder are converted into flake powder. The effect of milling time on the morphology of powders as well as the effect of initial pickling, before and after milling on the final conductivity of polyurethane adhesive has been investigated. Analyses performed on the samples included FESEM, EDX, XRD, electrical conductivity, Raman spectroscopy, FT-IR and mechanical properties of adhesives. Also, the sedimentation status for both spherical and flake fillers inside the polyurethane adhesive has been investigated. The effect of filler shape on percolation threshold and maximum conductivity is also discussed. The effect of an electric field (joule heating) on the electrical conductivity of four different systems of polyurethane/multi-walled carbon nanotubes, graphite, spherical and flake copper particles has been investigated. In the Joule effect test, the adhesive electrical conductivity and surface temperature of the samples were measured. It was observed that all four systems exhibit a negative temperature coefficient by applying an electric field. Mechanisms for tests of electrical conductivity, joule effect, and lap-shear are provided. The results of milling showed that in the wet state, despite the longer time to change the morphology from spherical to flaky than in the dry state, but the resulting powder had less impurities and showed better electrical conductivity. It is observed that with the deformation of the filler from spherical to flake, the maximum electrical conductivity increases from 24/5 S/cm to 41/6 S/cm. This means that the maximum electrical conductivity is increased 1/7 times. In addition, the percolation threshold is reduced from 50 wt% to 45 wt%; That means the percolation threshold decreases 10%. It was also observed that by changing the morphology from spherical to flake, the sedimentation time increased 1/7 times and the tensile strength of the composite increased 1/14 times.