The performances of interfacial transition zones(ITZ) in concrete under equal compressive strengths were studied quantitatively by the backscattered electron image analysis and nanoindentation. The results indicate that mineral admixtures improve the performances of ITZ to the different degree, also increase the heterogeneities; a mixture of metakaolin(MK) and limestone powder(LP) can decrease the thickness of ITZ, and reduce the increase value of elastic modulus remarkably, and meanwhile it improves the elastic modulus in matrix; however, the improving function of fly ash(FA) on ITZ shows the decrease of the increase value of elastic modulus only.