beta-Polypropylene/poly (styrene-co-acrylonitrile) blends (beta-PP/AS) were prepared with PP, a novel supported beta-nucleating agent (beta-NA) and AS (method one) or beta-nucleated PP and AS (method two). The influence of AS on the beta-nucleation for beta-nucleated PP has been analyzed. The results indicated that PP with high content of beta-crystal was obtained by adding beta-NA into PP. The DSC studies showed that AS and its content had little effect on crystallization and melting characteristics of beta-nucleated PP, and the content of beta-crystal calculated from WAXD is higher than 0.94 in all blends. beta-PP/AS blends with high content of beta-crystal were obtained easily. AS dispersed mainly into beta-spherulite of PP as small spherular particles, and the integrity of beta-spherulite decreases gradually with the increase of AS content. The etched experiment also proved that beta-NA dispersed in the AS phase or interface between PP and AS. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.