Multilayer materials containing alternating layers of isotactic polypropylene (iPP) and alpha-nucleating agent (NA)-filled iPP (PPN) were fabricated. Structural analysis presented that a sandwich structure of transcrystallinity(TC)/alpha-spherulites/TC was generated in each iPP layer and the TC structure consisted of alpha- and beta-crystals (TC alpha and TC beta). Different from traditional methods, the TC beta originated from the multilayered distribution of alpha-NAs was reproducible and tunable, so that its competitive growth with TC alpha was investigated. It was demonstrated that the confined growth of TC alpha around layer interfaces encouraged the beta-nuclei generation and the confined space of iPP layer determined the growth of TC beta. When the layer numbers reached 64 and 0.7 wt% alpha-NAs was introduced, the TC structure including 86.7% TC beta almost occupied each iPP layer, leading to the distinct improvement of mechanical strength and flexibility. Accordingly, this work provided a promising strategy for fabricating high-performance iPP products by controlling the distribution of alpha-NAs.