Blood compatibility and cytocompatibility are key requirements of blood-contacting biomaterials for biomedical applications. Here, we showed the general zwitterionic surface modification of cellulose membrane (CM) substrates, via surface-initiated atom transfer radical polymerization (SI-ATRP), to enhance the anti-biofouling ability without compromising the cytocompatibility of the substrates. Robust X-ray photoelectron spectroscopy (XPS) characterization revealed the successful construction of three zwitterionic brushes, which significantly increased the hydrophilicity of the CM substrates. The zwitterionic brushes-modified CM substrates can significantly reduce the non-specific adsorption of proteins, platelet adhesion and cell attachment, indicating a generally and significantly improved anti-biofouling ability, which is comparable to that of the benchmark anti-fouling poly(ethylene glycol) (PEG) surface. Inspired by the varied in situ cell morphology observed on different substrates, we further investigated the cytocompatibility of the zwitterionic coatings and showed the general cytocompatibility of zwitterionic brush-modified CM surfaces based on both 2D (cell cultured with zwitterionic surfaces) and 3D cell cultures (cell encapsulation in zwitterionic hydrogels). This work provides a promising general approach to enhancing the blood compatibility of cellulose-based materials without compromising their cytocompatibility. The cytocompatibility observation may enrich the perceptions of the zwitterionic modification of substrates and may be beneficial for the in vivo applications of zwitterionic materials.