The aim of this paper is to report the recent laboratory work on the synthesis of novel Ru(Ⅱ) polypyridine complexes and the studies of their interaction with DNA. The first part describes the syntheses and crystal structures of several novel polypyridine ligands containing imidazole or Schiff base moiety and their Ru(Ⅱ) complexes. The second part focuses on the influences of the shape, size and substitute groups of intercalative ligands and co-ligands on the binding modes, intensities and enantioselectivities of the complexes to DNA. The interactions of Ru(Ⅱ) complexes to different native DNAs are also compared. Certain regularity between the selection of a particular binding mode and the structure of complexes and:or DNA was observed. The final part of the paper reports the preliminary studies on a new DNA-mediated luminescence quenching assembly. The experimental results seem to support the notion that the p-stacked bases of DNA polymer maybe offer a pathway for electron transfer.