Block copolymer, method of forming the same and method of forming pattern

A block copolymer is provided. According to an embodiment of the present invention, the block copolymer comprises a first block represented by the following formula 1 and a second block represented by the following formula 2. COM1 and COM2 are independently selected from a group including polystyrene, polymethylmethacrylate, polyethylene oxide, polyvinyl pyridine, polydimethylsiloxane, polyferrocenyldimethylsilane and polyisoprene, R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms, x is 10 to 500, a is 1 to 50, R2 is hydrogen or an alkyl group having 1 to 10 carbon atoms, y is 10 to 500, and b is 1 to 50.