The prevention of coagulation processes and immune reactions at the interface of blood to biomaterials is a demanding requirement to enhance the hemocompatibility of biomedical products (e.g. cardiovascular implants, catheters, medical membranes). With this objective strategies for coating technologies are being developed, utilizing synthetic or naturally occurring inhibitors for the functionalisation of surfaces. Systematic analyses of the interaction of human whole blood with model substrates serve to clarify the molecular and physical-chemical factors, which trigger the humoral and cellular immune defense. These analyses further support the development of blood-compatible polymer coatings by quantifying the inhibitory effect of immobilized substances.