Modified polymerization initiator, and conjugated diene copolymers using the same

PURPOSE: A modified polymerization initiator is provided to prepare a conjugated diene-based compound in which the end is modified, having excellent braking power, wear performance and fuel efficiency and to perform the coupling capable of improving the molecular weight through the coupling reaction of the conjugated diene-based compound. CONSTITUTION: A modified polymerization initiator is obtained by modifying a polymerization initiator with a pyridine-based compound represented by chemical formula 1, wherein R1 and R2 are the same or different and represent hydrogen or C1~10 alkyl group; and n is 2~5. The molar ratio of a pyridine-based compound represented by chemical formula 1 to a polymerization initiator is 0.01:1~0.9:1. The terminal-modified conjugated diene-based compound is prepared using the modified polymerization initiator.