AbstractThe orientation of crystals in spherulites of modifications I and II of polybutene‐1 was studied by micro‐x‐ray diffraction. Changes in such micro‐x‐ray diffraction patterns were measured in various regions of the spherulites as a function of strain and time. The relationship between micro‐x‐ray diffraction from parts of spherulites and macro‐x‐ray diffraction from entire spherulites is discussed. Changes are resolved into contributions arising from (1) deformation of spherulites with change in crystal orientation and (2) transformation of crystals from modification II to modification I.