A decoding method includes performing a first decoding method and performing a second decoding method when decoding of the first decoding method fails. The first decoding method includes updating multiple variable nodes and multiple check nodes using probability values of received data. The second decoding method includes selecting at least one variable node from among the multiple variable nodes; correcting probability values of data received in the selected at least one variable node; updating the variable nodes and the check nodes using the corrected probability values; and determining whether decoding of the second decoding method is successful.