The paper presents data on the sulfate resistance of binary and ternary blended cements with three types of supplementary materials (SM): limestone filler, slag and natural pozzolana (volcanic tuff). The substitution level of portland cement, within the blended or composite cements, was 20%. Correlations between the mechanical strength and the type and kinetic of sulfate corrosion processes are presented in this paper. The nature and microstructure of the corrosion products as well as the influence of the type and dosage of SM in blended cement is also presented.