This paper mainly presents a construction of LDPC codes based on symplectic spaces. By two subspaces of type (m, r) to produce a subspace of type (m + 1,r) or (m + 1,r + 1) in \(\mathbb{F}^{2v}\) , we use all subspaces of type (m,r) to mark rows and all subspaces of type (m + 1, r) and (m + 1, r + 1) to mark columns of check matrix H. A construction of LDPC codes has been given based on symplectic spaces. As a special case, we use all subspaces of type (1,0) to mark rows and all subspaces of type (2,0) and (2,1) to mark columns of check matrix \(H_1\), in \(\mathbb{F}^4_q\), the cycles of length 6 of \(H_1\), is further discussed.