Biomechanical testing of connective tissue is usually done on whole tissue. Studies of the mechanical properties of each component of the tissue, however, are important for elucidating the connection between the functional properties and the molecular structure. Enzymic degradation of one component at a time followed by mechanical testing was employed. The specificity of enzymes used was ascertained with mechanical tests on collagen films from purified, reconstituted collagen after enzymic treatment. The study shows that collagen is the component which is mainly responsible for the tensile strength of skin and aorta, while the toe-part of the 'stress'-strain curve of aorta is determined by both elastin and collagen. The hyaluronic acid does not seem to play any role in the static mechanical properties of skin and aorta as evaluated by means of the present method.