A highly crystalline polypropylene for forming film which is obtained by subjecting to the molecular weight degradation a propylene homopolymer obtained by the polymerization of propylene over a stereoregulating catalyst and which has:(a) a melt flow rate, MFR, in the range of 1 to 10 min determined in accordance with ASTM-D-1238;(b) a ratio Q which is the ratio of weight average molecular weight M.sub.W to the number average molecular weight M.sub.N, namely, M.sub.W /M.sub.N, in the range of 2.5 to 4.0;(c) a density of at least 0.9070 g/cm.sup.3 or more;(d) the cold xylene soluble matter (CXS) in the range of 2.5% by weight at the highest.The highly crystalline polypropylene will produce film endowed with good transparency, stiffness, impact strength and resistance to blocking, in improved cost performance, which could to some extent be antagonistic to each other.