Amorphous hydrogenated carbon (a-C:H) films have been expected a surface modification coating to medical appliances [1]. In this study, we focus on the a-C:H film deposition in order to improve biocompatibility of the synthetic vascular graft. It is well known that a-C:H film has been expected to improvement of biocompatibility. However, evaluation of the biocompatibility, which is deposited a-C:H film on a synthetic vascular graft inner-wall, has not been reported enough.