The effects of concentration of nucleating agent N, N, N-tris-tert-butyl-1, 3, 5-benzene-tricarboxamide on the optical properties, mechanical properties, crystalline morphology, melting and crystallization behaviors of PP were investigated. The results show that the haze decreases significantly, the gloss is improved drastically, flexural modulus increases, while the tensile strength and notched impact strength change little, the spherulite size decreases drastically, melting point, crystallization temperature and the crystallinity improve after PP is modified with this nucleator.