Owing to its high mechanical strength, chemical inertness, low frictional coefficient, high wear and corrosion resistance properties and so on, carbon nanotubes (CNTs) films have emerged as a potential material for biomedical applications. In order to investigate the blood compatibility properties of CNTs films synthesized on the silicon (Si) substrate using thermal chemical vapor deposition, the blood compatibility was evaluated in vitro by the platelet adhesion and the activated partial thromboplastin time (APTT). The experimental results demonstrated that the Si-CNTs films reduced thrombus formation by minimizing the platelet adhesion, activation , aggregation and had a tendency to retard the intrinsic coagulation activities of blood due to a higher APTT compared to Si, lower temperature isotropic pyrolytic carbon (LTIC) and Polydimethylsiloxane (PDMS) materials. Further, we found that hydrophobic surfaces are more prone to direct cellular motility in comparison with hydrophilic surfaces. It is concluded that CNTs films on the Si substrate were effective for improvement of blood compatibility.