In this study, a kind of self-assembly â nucleating agent (TMB-5) with changeable geometry, and intense shear field provided by microinjection machine, were simultaneously employed to address the long-standing question about the possibility to cultivate highly-oriented â-crystals. The experimental results showed that the absorption of PP chains on the surface of â nucleating agent was the key factor to dictate the epitaxial crystallization under flow field. For dot-like TMB-5, it preferred to tumble and rotate following Jeffery orbits. In this case, the flow-induced á-nuclei in the bulk materials were prevailing and only few â-crystals were generated on the surface of â nucleating agent or the oriented á-crystals. When it came to fibrous TMB-5, it’s difficult for slender particles to rotate freely. The stretched polymer chains generated by flow could not crystallize into á-crystals, but continually deposited on the surface and became â-precursors, which further induced adjacent polymer to crystallize into â-crystals. That is, with the applied flow, the well-aligned fibrous â nucleating agent replaced the stretched molecules to trigger the oriented epitaxial growth of lamellas, into hybrid shish-kebab composed of â-crystals. This work provided a new manipulated strategy to tailor the crystalline structure of PP and enhance its mechanical performances.