This study Investigates properties of Ultra High Strength Cement Paste using mineral admixtures depending on the contents of CASB. The results are as following. On the flowability corresponding to the contents of CASB, it decreased greatly caused by increase of viscosity on the 5% of CASB. However, it increased slightly over the 5% of CASB because restraint water set free by the improvement of particle size distribution. On the flowability corresponding to the BFS types, it was the biggest BFS I when the flow property was relatively big, and BFS III was opposite tendency. In these facts, the flowability of Ultra High Strength Concrete related with the improvement of particle size distribution. The compressive strength was high in the case BFS I was used and the contents of CASB was increased. it was caused by filling up effect of CASB for capillary void Sized 100 nm and more as SEM and Porosimeter. If the plasticity and flowability as superplasticizer of CASB were established, it could be a new efficient material for Ultra High Strength Concrete.