Ti-O film was widely accepted as a bio-compatible material particularly due to its good blood-compatibility,say anti-thrombogenicity,nevertheless the underlying mechanism of anti-thrombogenicity remains unclear up to now.In this paper,we combine the anti-thrombogenicity evaluation results with the electrochemical interfacial behaviours of the Ti-O film to interpret the interaction between the Ti-O film surface and the blood from the point view of electrochemistry.Ti-O films were synthesized by unbalanced magnetron sputtering technique,and characterized by XPS and XRD respectively.The electrochemical properties of the film were investigated by Electrochemical Impedance Spectroscopy (EIS) and Mott-Schottky.The blood-compatibility of antithrombogenicity is evaluated in-vitro by platelet adhesion measurement and LDH test.The EIS measurements show that the reducing extents of impedance of Ti-O film in fibrinogen containing electrolyte (PBS),vary with the specimen with different surface stoicheiometric compositions.Mott-Schottky plots show that the Ti-O film of more negative flat energy band potential (-1.0~-1.2eV vs.SCE) and higher carrier concentration (1026~1027/m3) possess better blood compatibility.The underlying principle in anti-thrombogenic behaviour of Ti-O film is discussed both thermodynamically and kinetically in perspective of interfacial electrochemistry.