ABS/iPP　composites　were　prepared　by　extrusion　processing　and　its　crystallization,　mechanical　properties　were　studied.　The　result　of　WAXD　showed　that　β-modification　was　induced　with　the　help　of　ABS　along　β(300)　lattice　pland,　and　α-modification　was　restrained.　When　the　content　of　ABS　was　5wt%,　the　relative　content　of　β-crystal　in　iPP　was　0.45,　and　the　crystallinity　was　66.94%.　The　results　also　showed　that　the　relative　content　of　β-crystal　was　hard　to　increase　continually,　because　the　crystalline　rate　was　too　fast　for　iPP　chain　segment　to　adjust　its　chirality　to　form　β-crystal.　It　was　found　from　DSC　that　the　crystalline　temperature　and　rate　of　iPP　was　increased　with　the　adding　of　ABS,　and　the　melting　peak　of　β-crystal　was　appeared　in　the　melting　curve　of　ABS/iPP　composites.　It　was　observed　in　POM　figures　that　β-crystal　of　iPP　chain　segment　was　crystallized　belong　ABS　chain　segment.　In　addition,　the　mechanical　properties　and　heat　distortion　temperature　were　increased.　In　conclusion,　ABS　can　be　used　as　polymeric　β-nucleating　agent　for　inducing　iPP　into　β-modification　and　improving　the　properties　of　iPP.