The formation of beta-cylindritic micromorphologic structure produced by pulling a Kevlar fiber from an isothermal crystallizing beta-nucleated isotactic polypropylene melt (at T-c=133 degrees C) has been studied by using polarized light microscope, phase contrast optical microscope, scanning electron and atomic force microscopes. The micrographs reveal a clearly interfacial shear zone, alpha-cylindrite, beta-cylindrite and beta-spherulites near the sheared layer. Some of the point-like beta-nuclei was not originated from the surface of the interfacial shear zone. A modified model based upon the theory of shear-induced crystallization can explain the phenomenon of polymorphic structure and the boundary shape near the interface without assuming epitaxial growth.