The development of Ru(ii) complexes as luminescent probes has attracted increasing attention in recent decades. In this study, the nanosized polymers of two Ru(ii) complexes Ru(phen) (dppz)(ClO ) (1, phen = 1,10-phenanthrolin; dppz = dipyrido3,2- :2',3'- phenazine) and Ru(phen) (Br-dppz)(ClO ) (2, Br-dppz = 11-bromodipyrido3,2- :2',3'- phenazine) with oligonucleotides were prepared and investigated as potential tumor-imaging probes. The formation of the nanosized polymers, which had an average width of 125-438 nm and an average height of 3-6 nm, for 1 and 2@oligonucleotides were observed through atomic force microscopy. The emission spectra indicated that the luminescence of 1 and 2 markedly increased after binding to oligonucleotides and double-strand DNA (calf thymus DNA), respectively. Moreover, further studies indicated that 1@oligonucleotides and 2@oligonucleotides can easily enter into tumor cells and selectively highlight the tumor area in the zebrafish bear xenograft tumor (MDA-MB-231). In summary, this study demonstrated that 1@oligonucleotides and 2@oligonucleotides could be developed as potential tumor-imaging luminescent probes for clinical diagnosis and therapy.