Abstract: Two noval nucleating agents SnB4 and SnD4 (stannic chloride, benzoic acid and p-tert-butyl benzoic acid) were prepared and employed in isotactic polypropylene (iPP). The iPP samples were studied using X-ray diffraction analysis, differential scanning calorimetry, and polarized light microscopy. The mechanical properties and Vicat softening temperature of iPP were also tested. It was found that the two nucleating agent improved the crystallinity and crystallization rate of iPP. Mechanical properties of the iPP were also somewhat improved, especially when SnD4 was used.