Carbon nanotubes (CNTs) have been largely investigated in various biomedical fields on the basis of their excellent physical properties and drug delivery performance. However, application capacities of CNTs in blood-contacting medical devices are given due attention though there have been increasingly accumulated experimental data showing promising potentials. Herein, we collected and showed research evidence that strong interactions of CNTs to plasm proteins are attractive and valuable features holding great application potentials for medical devices and implants used in blood-contacting environments, while blood compatibility has been a big challenge faced by this kind of devices. This review introduces the strong and nonspecific plasm protein adsorptions of CNTs due to their high purity of carbon composition and nanostructures, followed by discussions on the implication of these interactions to blood coagulation and complement activation, aiming to sort out and provide insights into the application potentials of CNTs in blood-contacting medical devices and implants in the context of anti-thrombosis and blood purification.