The use of self-compacting concrete (SSC) which is capable of flowing in farm work and congested reinforcement without any mechanical vibrator fill the concrete voids with its high paste content is highly durable and Economical. It is believed that this kind of property is attained by achieving high placing density among the constituents of concrete with satisfactory workability properties. A comparative experimental studies on the arrived M40 grade SCC is carried out with replacement of ordinary port land cement (OPC53) (IS 12269) with OPC53S (per IS4031) varying from different percentages to determine optimum replacement. Fresh properties of SCC reveal the enhancement of workability satisfying permissible limits.