A class-D amplifier includes an error amplification circuit, a duty signal generator, a level selection circuit, a driver and control block and an output stage. The class-D amplifier divides peal levels of an error signal into multi-level and changes a scheme for modulating the error signal when the error signal crosses each level boundary of the multi-level thereby to have an effect such as the error signal is folded. Therefore, the class-D amplifier drives output nodes with multi-level and thus the class-D amplifier may increasing efficiency while reducing EMI.