Abstract: ZK60 magnesium alloy was solution-treated at different temperature (200-300℃). The microstructure was observed by scanning electron microscope (SEM) and corrosion resistance of the alloy in mass fraction of 3.5% NaCl solution was studied by the mass loss method and electrochemical method. The results indicate that the content of second phase in the alloy decreased with the increase of solution temperature, and the distribution of second phase changed from continuity into discontinuity. The corrosion rate increased first and then reduced with the increase of solution temperature. The optimal corrosion resistance was obtained at solution temperature of 300℃, and the corrosion rate, free corrosion current density and free corrosion potential were 4.575 2 mm·a^-1, 0.011 639 mA·cm^-2, -1.511 0 V, respectively.