The degradation of sulphoaluminate cement (SAC) subjected to wet-dry cycles in sulfate solution was studied in this paper.The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM).The results show that the surface spalling and microstructure degradation increase significantly with the increasing of wet-dry cycles and water to cement ratios (w/c) when the aggressive medium is 5% sodium sulfate solution.The degradation of SAC specimen caused by 5% sodium sulfate solution is significantly higher than that of specimen caused by 3% sodium sulfate solution.At the initial period of sulfate attack, magnesium sulfate and sodium chloride can reduce the degradation of SAC specimen when the sulfate ions concentration is a constant value.In addition, the degradation of SAC specimen seems to be slightly higher than that of OPC subjected to the wet-dry cycles in 3% sodium sulfate solution.