The conventional encoding method of Low Density Parity Check（LDPC）Code often cannot put the girth and nonsingularity of check matrices into consideration at the same time

which has negative effects on the performances of encoding and decoding

and increases the decoding complexity.A low complexity method to construct check matrices is presented.A matrix with properties of girth of 10

column weight of 2

nonsingularity

and approximate lower triangular is generated by constructing the sub-matrix Aand sub-matrix Bstep by step.Due to these features

some advantages such as better decoding performance

more suitable for partial response channels

lower encoding and decoding complexity are shown.The simulation result shows that the proposed coding scheme has lower complexity than the code with girth of 10.It also presents better decoding performance than common code with girth of 6in AWGN channels after Belief Propagation（BP）decoding algorithm.