The work aims to study the corrosion inhibition effect and mechanism of sodium silicate on AM60 magnesium alloy in simulated vehicle coolant medium. The corrosion inhibition effect of sodium silicate on AM60 magnesium alloy in simulated vehicle coolant medium was studied by means of electrochemical methods including polarization curves and electrochemical impedance spectroscopy (EIS). Effects of sodium silicate concentration, simulated coolant temperature and immersion time on corrosion inhibition efficiency were inspected. The corrosion inhibition mechanism of sodium silicate was also discussed. Concentration of Na2SiO3 had great influence on corrosion inhibition efficiency, and its optimumconcentration was 0.8 mmol/L and the corrosion inhibition efficiency of sodium silicate was 95.87%. Inhibition efficiency of the sodium silicate was up to 36.08% at high temperature (80 ℃) in the simulated coolant. Hence the sodium silicate provided inhibition protection on AM60 magnesium alloy. At the early stage of immersion, corrosion inhibition efficiency of Na2SiO3 on AM60 magnesium alloy was 17.47% and then amounted to 72.38% after 10 hours. When concentration of the sodium silicate is 0.8 mmol/L, the corrosion inhibition efficiency is the highest. It decreases as the medium temperature increases and increases as the immersion time in the simulated coolant medium increases. The sodium silicate acts as an anodic type inhibitor, and the corrosion inhibition mechanism of sodium silicate can be interpreted as the fact that insoluble compound of MgSiO3 can be generated by the reaction of SiO32? with Mg2+ (produced by corrosion). MgSiO3 deposites on the surface of alloy and forms a layer of protective film, thus inhibiting further metal ionization.