Abstract: The effect of rolling and forging on the microstructure and corrosion behavior of LZ91 alloy was investigated using an electron probe micro-analyzer, immersion and electrochemical tests. Results showed that the area fraction of the β-Li phase remained unchanged, and the grain size of the β-Li phase decreased after forging. The as-rolled forged alloy (FR-LZ91) exhibited the highest area fraction of the β-Li phase and the longest grains. The corrosion resistance of the forged LZ91 alloy increased due to grain refinement that prevented further corrosion during the immersion test. Among the experimental alloys, FR-LZ91 showed the highest resistance of corrosion film and charge transfer resistance values due to its protective film caused by the high area fraction of the β-Li phase.