Compressive strength，internal phase migration and pore structure characteristics of various cementitious materials before and after accelerated erosion by carbonated water were compared. The results show that the strength development is limited after carbonated water erosion， the Ca（OH）₂ and CaCO₃ contents are reduced at the same time， the pore size becomes larger and the proportion of harmful pores increases. The cementitious system with hydrate calcium silicate gel and Ca（OH）₂ as the main hydration products is most vulnerable to carbonated water erosion， and the cement-based material with higher content of Ca（OH）₂ has weaker resistance to carbonated water. The resistance of carbonated water erosion of the cementitious system with ettringite as the main hydration product is significantly enhanced.