The fabrication of composites based on different fillers has gained numerous considerations in the past decades in different areas of biomedical research. It is necessary for the chosen polymeric material as a continuous phase to have good compatibility with the fillers to form a unique biomedical system. Interfacial interactions between components of the system are also important for establishing characteristics of the resulting biomedical material. In this work, one polymer based on modified polysulfone (PSF) was considered a host matrix where modified carbon nanotubes with hydroxyl groups were added for the scope of fabricating a biocompatible material. A chlorometilation reaction was used to create aldehyde groups linked to PSF, which was further cross-linked by an oxidation reaction and acetilization of poly(vinyl alcohol) (PVA) to obtain a new modified PSF with side PVA groups. For comparison only, the new material was analyzed with another system containing PVA as a matrix where different concentrations of modified carbon nanotubes were added. The content ratio of modified carbon nanotubes varied between 0.5 to 5 wt%. Each prepared composite system was investigated by contact angle measurements. The compatibility with blood was determined by theoretical calculation and experimental analysis such as hemocompatibility. Materials were proved to be biocompatible, which leads to their recommendation as blood-contacting materials.