High entropy alloy (HEA) thin coatings have been deposited on steel substrate of a mixed alloy power made of high purity elemental aluminium, cobalt, chromium, copper, iron and nickel by electron beam evaporation and effect of the Al content of the coating on its structural, surface morphology and electrical properties were investigated. The results of X-ray diffraction (XRD) showed that coatings were typical dendrite and interdendrite structures with different aluminum contents. The coatings’ surface chemistry components were basically similar composition as originally designed alloys by electron probe micro-analyzer (EPMA). Atomic force microscopy (AFM) indicated that modified the surface of all coatings were very smooth and uniform. HEA coatings exhibited wide passive regions, which extended ＞700 mV in aqueous solutions of H2SO4 and NaCl. A large corrosion potential (-129 mV) and a small corrosion current density (≈2.2×10-6 A/cm2) clearly revealed that the corrosion resistance of the Al0.5FeCoCrNiCu coating was superior to that of the coatings.