Abstract: Amorphous Mg_0.9Ti_0.1Ni_0.85Co_0.15 alloy was coated with graphite and nickel powder by ball milling.SEM indicated that there was a graphite or nickel thin layer on the surface of the alloy.X-ray energy spectrum analysis showed that after coated with graphite powder,the C content at the surface of the alloy increased,and the mass and atomic contents of Mg decreased from 22.74% to 22.23%,and from 36.43% to 32.94%,respectively,which decreased the corrosion probability of Mg in alkali solution;after coated with nickel powder,the mass and atomic contents of Ni at the surface of the alloy increased from 59.89% to 60.04%,and from 40.63% to 41.02%,respectively,which indicted that a nickel-riched layer was formed.This nickel-riched layer can protect the alloy from corrosion in alkali solution.Charge-discharge cycle tests showed that after 30 charge-discharge cycles,the capacity retained for the graphite coated alloy,the nickel coated alloy,and the uncoated alloy was 32.05%,41.26% and 17.88%,respectively.This indicates the graphite coating and the nickel powder coating can increase the cycle stability.Polarization curves showed the antico-rrosion characteristic of the Mg_0.9Ti_0.1Ni_0.85Co_0.15 alloy electrode in KOH solution was improved by graphite or nickel coated.