A process for preparing a metal styrene polymer composite having nano metallic particles deposited thereon is disclosed, which includes a) undergoing free radical polymerization of styrene and an optional co-monomer in the presence of a persulfate initiator and a chain transfer agent; and b) contacting the resulting styrene oligomer or copolymer of styrene and the co-monomer from step a) with an aqueous solution containing a noble metal ion dissolved therein, so that the noble metal ion is reduced to element form particles and deposit on the styrene oligomer or copolymer of styrene and the co-monomer by sulfates on the oligomer or copolymer in the absence of a reducing agent.