A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate parity bits; a parity permutator configured to perform parity permutation by interleaving the parity bits and group-wise interleaving a plurality of bit groups including the interleaved parity bits; and a puncturer configured to select some of the parity bits in the group-wise interleaved bit groups, and puncture the selected parity bits, wherein the parity permutator group-wise interleaves the bit groups such that some of the bit groups are positioned at predetermined positions, respectively, and a remainder of the bit groups are positioned without an order within the group-wise interleaved bit groups so that the puncturer selects parity bits included in the some of the bit groups positioned at the predetermined positions sequentially and selects parity bits included in the remainder of the bit groups without an order.