Using synchrotron SAXS and WAXS, we investigated crystalline structures including crystallite size, lamellar thickness, long spacing of syndiotactic polypropylene （sPP） and poly（ethylene-co-octene） （PEcO） that crystallized from the sheared melt. The independence of the shear effects on the crystalline structures and the shear related lamellar orientation indicate the stable mesophase. Experiments on the different shear effects on polymer various crystalline structures confirm the multi-step polymer crystallization process.
