The copolymerization of styrene with I-alkene (1-hexene, 1-decene and 1-hexadecene) has been tested using combined diphenylzinc-additive initiator systems, including diphenylzinc (Ph2Zn), a metallocene and methylaluminoxane (MAO). The metallocene were biscyclopentadienyltitanium dichloride, bis(n-butylcyclopentadienyl)titanium dichloride, cyclopentadienyltitanium trichloride and bisindenylzirconium dichloride. For Ph2Zn-metallocene-MAO systems, titanocenes gave mainly syndiotactic homo polystyrene irrespective of the styrene/1-alkene proportion in the initial feed. Systems including Ind(2)ZrCl(2) were able to copolymerize styrene I-alkene with the copolymers incorporating alkene in a lower proportion than the present in the initial feed.