There are many studies on the design and synthesis of metal complexes due to their potential applications as functional materials in the area of magnetism, nonlinear optical behaviour, porosity and luminescence 1-3. The research of the interactions between metal complexes with DNA plays an important role in the development of DNA molecule probes and chemotherapeutics. We designed and synthesized a new complex based on thiadiazole. Furthermore, we studied the interaction between the complex and DNA by UV absorption titration, fluorescence titration. The result reveals that the intercalation is the main binding mode between the complex and DNA. EXPERIMENTAL UV spectra were carried out by a Shimadzu UV-2450 spectrometer. Elemental analysis was performed on a Perkin-Elmer 240C element analyzer. The fluorescence spectra of the complexes bind to DNA were recorded on a F-4500 equipped with a xenon lamp and a quartz carrier at room temperature. Synthesis of [Mn(DMTD)(1,10-phen)2Cl] (1): A mixture of MnCl2•6H2O (39.6 mg, 0.2 mmol), 2,5-dimercapto-1,3,4thiadiazole (DMTD) (60 mg, 0.4 mmol), 1,10-phenanthroline (198.22 mg, 1 mmol), NaOH (16 mg, 0.4 mmol) and distilled water (10 mL) was sealed in a 25 mL teflon-lined stainless steel vessel and heated to 150 ºC for 36 h. After slowly cooling to room temperature, the products were orange crystals and