The experiment was to avoid cruor on the surface of the mechanical heart valve. Firstly diamond-like carbon (DLC) films were deposited on the mechanical heart valve,Al2O3,316 L stainless steel and silicon substrates by the pulsed laser deposition (PLD) at same experiment condition. The result demonstrated that diamond-like carbon film exhibited the best adhesion to the mechanical heart valve. Secondly the structure and composition and topography of diamond-like carbon film on the mechanical heart valve were measured by the visible Raman spectroscopy and the X-ray photoelectron spectroscopy (XPS) and the atomic force microscopy (AFM). Finally human umbilical cord vein endothelial cells (HUVEC) were seeded on diamond-like carbon film on the mechanical heart valve and cultured in vitro. Raman spectroscopy revealed that disorder peak was at 1341.66 cm－1and graphite peak was at 1528.17 cm－1. XPS spectroscopy revealed that there was 21.45% of sp3 in the film. AFM revealed that the roughness average of the film was 26.4 nm. Human umbilical cord vein endothelial cells could proliferate on diamond-like carbon film very well. The result demonstrated that diamond-like carbon film on the mechanical heart valve deposited by pulsed laser deposition had good cell compatibility and could be covered with human umbilical cord vein endothelial cells fully so that it is possible to avoid cruor on the surface of the mechanical heart valve.