Abstract： Background Recently,it has been proposed that the autoantibodies against various cardiovascular receptors play a role in the pathogenesis of primary hypertension.In this study,we aimed to identify whether or not there are autoantibodies against cardiovascular L-type Ca2+ channels in patients with primary hypertension.Methods A peptide corresponding to the sequence 2-16 of the alc-subunit of L-type Ca2+ channel was used as an antigen to screen the autoantibodies from 90 patients with primary hypertension and 45 healthy controls by an enzyme-linked immunosorbent assay(ELISA).The clinical data of 90 hypertensive patients were compared between patients with and without these autoantibodies.Results Serum from 3(6.7%)of the 45 healthy controls,33(36.7%)of 90 hypertensives showed positive responses in ELISA(P<0.01).The prevalence of such autoantibodies in two subgroups of hypertensives with coronary heart disease(9/21,57.1 4%,P<0.05)and left ventricular diastolic dysfunction(28/63,44.4%,P<0.05)was higher than in those without the corresponding complications.And the patients with such autoantibodies had lower E/A than patients without such autoantibodies(O.803±0.191 vs 1.004=L+0.322,P=0.002).Conclusion There are autoantibodies against vascular L-type Ca2+ channels in patients with primary hypertension.