The growth front of isotactic polypropylene (iPP) spherulites is studied with series of in-situ microanalyzing techniques: conventional source infrared microspectroscopic (CS-mu IR), polarized infrared microspectroscopic imaging (SR-mu PIR), and scanning X-ray microdiffraction (SR-mu SXRD). By SR-mu SXRD, the actual growth front boundary of spherulite was clearly defined, which is the boundary observed with an optical microscope. Measurements of CS-mu IR and SR-mu PIR on growing spherulites reveal that a growth front layer (GFL) with high content of conformational ordered long helices exists outside the growth front of spheurlite, which has a thickness up to 30 mu m above 142 degrees C. These long helices preferentially orient perpendicular to the radial direction of spherulite, whose growth fashion seems correlating with the growth of spherulite.