alkylaluminum and cocatalyst and then introducing the activated main catalyst into a reactor containing monomers or iii adding alkylaluminum to monomers before the monomers are introduced into a reactor introducing the monomers with the alkylaluminum into the reactor and then introducing main catalyst activated with a cocatalyst to the reactor and the activation by bringing main catalyst into contact with cocatalyst is preferably conducted at 0 to 150 u00b0 c for 0 1 to 240 minutes and more preferably for 0 1 to 60 minutes the amount of the main catalyst metallocene compound is not specifically limited but is suitably 10 u2212 8 to 1 0 m on the basis of concentration of central metal in reaction system and ideally 10 u2212 7 to 10 u2212 2 m syndiotactic styrene polymers and copolymers obtained by polymerization using the catalyst system of the present invention can be controlled in a molecular weight range of 1000 to 10 000 000 and in a molecular weight distribution range of from 1 1 to 100 by controlling the kinds and the amounts of a main catalyst and a cocatalyst reaction temperature reaction pressure and concentration of monomers hereinafter the present invention will be described in more detail through examples and comparative examples examples are presented on the exemplary purpose but can not be construed to limit the scope of the present invention 3 80 g 27 mmol of hexamethylenetetramine 23 ml 124 mmol of 2 6 diisopropylphenol and 0 1 g of p toluenesulfonic acid are put into a 100 ml shlenk flask without solvent and heated up to 110 u00b0 c as the temperature rises solids are melted and homogenized thereby turning into a dark brown solution 12 hours later 7 ml 37 8 mmol of 2 6 diosoprppylphenol is.