Abstract: A parity check matrix construction method for constructing a non-binary parity check matrix defining a non-binary LDPC code. In particular, a parity check matrix construction method for setting codewords able to stably give a superior decoding performance is provided. For this reason, the non-binary non-zero elements are selected so that the determinants of the partial matrices corresponding to the cycles in the parity check matrix do not become 0. Due to this, a non-binary parity check matrix able to give large weight codewords is constructed.