Abstract:The method of molten salt electrolysis was applied for boronizing of Titanium. The experiment was carried out at 930 ℃ for1h, using Borax as the source of boron and Calcium Chloride as supporting electrolyte. The effects of current density on the microstructure and the thickness of the TiB2/TiB layer were investigated and the electrochemical behavior of cathode in molten salt was studied by Cyclic Voltammetry. XRD, SEM and EDS means were applied to analyze phase composition, microstructure and morphology, element content of the borides layer respectively. The results show that the bording layer was composed of TiB2 and TiB, with the thickness of the TiB2 layer being 1.2 to 4.5μm depending on the current density; the thickness of the TiB2 layer changes nonlinearly with the increase of the current density；Analysis of the Cyclic Voltammetry curve shows that the cathodic reaction was mainly the reduction of sodium ions to sodium, then boron was reduced by sodium from B2O3; the borides layer was formed by the diffusion of B atoms into titanium substrate at high temperature.