The lossless coding method includes selecting one of a first coding method and a second coding method, based on a range in which a quantization index of energy is represented, and coding the quantization index by using the selected coding method. The lossless decoding method includes determining a coding method of a differential quantization index of energy included in a bitstream and decoding the differential quantization index by using one of a first decoding method and a second decoding method based on a range in which a quantization index of energy is represented, in response to the determined coding method.