Two sets of experiment have been achieved with rubella hemagglutination–inhibition test. First, rubella antibodies have been determined on serum and capillary blood samples to estimate the sensitivity and specificity of adsorbent paper-disc method for collection of specimens. Second, rubella antibodies have been studied in serum samples after treatment by kaolin or by heparin – manganous chloride to remove non-specific inhibitors of rubella hemagglutination. Results have shown that adsorption of capillary blood on filter paper disc and treatment of serum by heparin – manganous chloride should be adequate to perform rubella hemagglutination–inhibition tests.