The synthesized cobalt(II) complex, CoPNBDENA and the binding of this complex with sheep genomic DNA were investigated by UV-Visible absorption and viscosity techniques. Also the interaction of sheep genomic DNA with the complex was studied using the agarose gel electrophoresis method. The results indicated that the complex interacted with DNA. The nature of the binding seemed to be mainly an electrostatic interaction between DNA and the cobalt(II) complex. Other binding modes such as hydrogen bonds may also exist in this system. In this study, after the interaction of DNA-CoPNBDENA, it was observed that the migration of the DNA band became slow as the amount of cobalt(II) complex was increased. This clearly demonstrates that the CoPNBDENA complex neutralizes the negative charges of DNA.