The crystallization of homopolymers yields a hierarchical structure in polymer materials, which substantially controls their physical properties. Therefore, the crystalline morphology of homopolymers has been one of the important research subjects in polymer science. This chapter summarizes the crystalline morphology formed in homopolymers, which is usually explained in many textbooks of polymer science. It describes more complicated morphology, that is, the crystalline morphology of block copolymers. The chapter also describes the characteristics of the crystal structure, lamellar morphology, and spherulite structure from the viewpoint of interrelation among them, and also experimental methods to quantitatively analyze these morphologies. The lamellar morphology formed in miscible blends is usually observed using small-angle X-ray scattering (SAXS) because its typical repeating distance is in the order of ~10nm. The spherulite is a sphere-shaped superstructure, and usually observed when crystalline polymers are quenched or slowly cooled from a homogeneous melt into low temperatures.