Abstract: The catalyst system disclosed herein comprises a combination or a chelate of a hydrocarbyl lithium compound with a bicyclic amine compound bridged together through nitrogen in each cyclic ring by means of 1-4, preferably 2-carbon atoms and each cyclic ring having at least one nitrogen and at least one other heteroatom in its cyclic structure selected from the class consisting of NR, O, S and PR. This catalyst system is particularly useful in the polymerization of vinyl compounds such as ethylene, propylene, styrene, butadiene, etc. The process for the polymerization of conjugated dienes produces polymers of excellent properties. For example, with butadiene-1,3 and other appropriate conditions, polybutadiene with high percentages of syndiotactic crystalline structure may be produced.