A method and an apparatus for controlling an interleaving depth are provided. The interleaving depth controlling method includes performing a modulo operation on an interleaving depth selected to be less than or equal to a maximum interleaving depth and a total number of codewords to obtain a number of remaining codewords; and comparing the total number of the codewords to the interleaving depth, when the number of the remaining codewords excludes “0”, to control the interleaving depth.