An apparatus and method for scrambling in a wireless communication system are provided. The apparatus includes a selector, a plurality of scramblers, and a plurality of modulators. The selector selects a scrambling scheme to be applied to a transmission bit stream according to a modulation scheme to be applied to the transmission bit stream. The plurality of scramblers scramble the transmission bit stream according to a scrambling scheme corresponding to each of a plurality of modulation schemes. The plurality of modulators modulate the scrambled transmission bit stream according to the plurality of modulation schemes.