Bit line selection circuit having hierarchical structure

Disclosed is a bit line selection circuit having hierarchical structure capable of preventing delay of operation speed due to signal loading by selecting a bit line with a sub bit line selection driver in a hierarchically shared bit line sense amp. The disclosed comprises: a bit line selection transistor unit for switching controlling a bit line between a cell array block and a bit line sense amp; a bit line equalizing signal generation unit for receiving a sense amp enable signal and a first and a second block signals and generating a bit line equalizing signal; a global bit line selection unit driven by output signal of the bit line equalizing unit and generating a first and a second global selection signals, a first and a second global selection bar signal and a bit line selection precharge signal; and a sub bit line selection driver unit for receiving the second global selection signal, the first global selection bar signal and the bit line selection precharge signal and generating a control signal controlling the bit line selection transistor unit.