Abstract: A propylene block copolymer with a high proportion of ethylene-propylene copolymer particles (rubber component) well dispersed in a propylene polymer exhibiting well-balanced rigidity and impact resistance can be obtained by using a solid catalyst for polymerization of olefins comprising (a) a solid catalyst component with controlled morphology, comprising magnesium, titanium, and a halogen atom, having an average particle diameter, specific surface area, and pore volume in a specific range, and having a pore size distribution in which an cumulative pore volume with a pore size of 100 Å or less is more than 50%, (b) an organoaluminum compound, and (c) an organosilicon compound. The block copolymer is very useful particularly for the application of vehicle parts such as a bumper and parts for household electric appliances.