Abstract: To improve biocompatibility of biomaterials and endow the surface with biological functions, a new type of composite coatings was developed using the natural biomacromolecule tannic acid (TA) and polyetheramine ED900 through a layer-by-layer self-assembly method. The behavior of ED900-TA complexation in water and the physical/chemical properties of the ED900-TA coatings were characterized using nanoparticle sizer, Zeta potential analyzer, UV-vis spectrophotometer, FTIR spectrometer, quartz crystal microbalance (QCM-D), and SEM. The effect of coatings on cell behavior was investigated in vitro. The anti-oxidative property was measured by 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and total antioxidant capacity assay kit (FRAP) assays. Finally, coating stability was evaluated by agarose insertion and incubation in cell culture medium. The results show the coatings being biocompatible and anti-oxidative. Depending on the surface microstructures, the coatings can be cytophilic or cytophobic. Besides, the coatings can withstand the shear force of insertion and the morphology is maintained up to 21 days in culture medium. This composite coating provides a new option for surface functionalization of biomaterials.