Abstract: Corrosion mechanism of nickel deposit on depleted uranium surface prepared by pulse plating was studied by scanning electron microscope (SEM), X-ray energy dispersion spectroscope (EDS) and electrochemical technology. The results indicate that in potassium chloride solution with 50 μg/g Cl~(-), the corrosion of nickel deposit on uranium surface occurs at it's pit and extends to the interface between uranium and nickel deposit. The (accumulation ) of corrosion product results in the cracking of nickel deposit. Because nickel is a cathodic coating for the uranium matrix, the galvanic corrosion will happen when they contact. The protection of nickel coating to uranium depends on the physical barrier of nickel coating to the corrosive medium. The densification of the nickel coating will (improve ) the corrosion resistant performance of nickel coating to uranium.