the invention provides for study properties of polypropylene (injection grade) / polypropylene (extrusion grade) blend filled with calcium carbonates. In four formulations of PP(Injection grade)/PP(Extrusion grade)) viz. 95/5, 90/10, 85/15 and 80/20 in ratio of weight percentage were prepared for injection molding machine. This PP(Injection grade)/PP(Extrusion grade) (80/20) blend was selected and investigated at different three fractions of calcium carbonate. The mechanical properties such as tensile strength and elongation test were investigated. The rheological properties such as melt flow index (MFI) and melt density were evaluated. The results indicated that incorporate calcium carbonate increase the (MFI), melt density and elongation decreased while increase the tensile strength. It was obtained that increase calcium carbonate content into PP(Injection grade)/PP(Extrusion grade) blends will increase the density. Taking into consideration, it was concluded that, the optimum composition provided the good mechanical, rheological properties and density is PP(Injection grade)/PP(Extrusion grade)/Calcium carbonate (80/20/22.5) wt%