The aggregate interface characteristics of sandstone, rust dye sandstone, surface rust sandstone, slate and marble were investigated by means of the computerized tomography(CT) technology, scanning electron microscope(SEM), energy dispersive spectromete(EDS) and microhardness(MH) and the mechanism of interface features of the above aggregates on mechanical properties of concrete were studied. It was shown that the microstructures of different aggregates interfacial transition zone(ITZ) vary considerably. The chemical composition, mineral composition and surface texture of different aggregates affect the quantity, shape, size and growth characteristics of the hydrated product of ITZ. The microhardness is well related to the molar ratio of CaO to SiO2 (nC/nS) of the ITZ. The higher nC/nS, the lower microhardness. The initial cracking strength of marble aggregate concrete is significantly lower than those of sandstone, slate and rust dye sandstone aggregate concrete. In the same load condition, the cracking area ratio of marble aggregate concrete is far higher than other aggregate concrete.