Ethylene-propylene random copolymer(EPH) toughened isotactic polypropylene(PP) alloy systems were melt blended using twin-screw extruder. Mechanical properties such as tensile and impact strength were measured using tensile tester and Izod impact tester, respectively. EPM rubber particle size. shape and distribution were observed from liquid nitrogen fractured and etched surface using scanning electron microscope(SEM). Also, corresponding microstructural deformation was analysed using SEM and optical microscope. Tensile test results revealed that yield strength and modulus were decreased with increasing EPM rubber content. However. yield strain was increased with increasing EPM rubber content. Izod impact strength was increased with increasing EPH rubber content at room temperature, however. remained almost unchanged at low temperature(-4$0^{circ}C$). Liquid nitrogen fractured surface showed that EPM rubber size and distribution were decreased with increasing EPM rubber content.