We outline a novel 3D graphical representation of DNA sequences, which can avoid crossing and overlapping of the corresponding spatial curve. And the advantage is that we can just consider two different conditions, but three conditions in other 3D representations. As application, we construct a 2-component vector whose components are the normalized leading eigenvalues of the L/L matrices associated with DNA sequence based on the two conditions, to examine the similarities/dissimilarities among the coding sequences of different species.