The compatibility between metakaolin(MK) blended Porland cement and superplasticizers and the properties of MK blended cement were investigated in this paper. Results show that the compatibility between MK blended cement and superplasticizers is reduced. However, the compatibility is enhanced when MK and ultra fine slag are incorporated in Portland cement together, also the compressive strength of MK blended cement is increased. The hydration products of MK blended cement were analysed by DTA and SEM.