Abstract: Objective To study the positive rates of autoantibodies in thepatients with malignancies as well as the locations of their target antigens in cells and identify the essence of their target antigens. Methods Sera of 385 malignancy patients as well as 140 healthy controls were detected with indirect immunofluorescence (IIF) method using antigens extracted from human epithelial cells (Hep-2). Results We detected 95 patients' sera with positive IIF results with westernblotting method. There are significant differences in positive rates, fluorescent patterns, and location of autoantigens in cells between concer group and health group(P＜0.05). Although with age growing, both have increasingly higher positive rates, concer group are much higher than those of control in every age group(P＜0.01). There is no significant difference among different malignancy groups(P＞0.05). Among 95 patients' sera with positive IIF results,90 of them were objected one or more positive bands. A few bands were confirmed as several known autoantibodies usually appearing in some autoimmune diseases according to standards provided by the kit, which included PM-SCL(2), Ku(7), CENP(5), M2(9)， RNP(4)， SS-A(7)， Jo-1(1), SS-A/SS-B(5), Rib-P-Protein(4). The autoantigen of most other bands were still unknown. Conclusion Dispite of age-related, autoantibodies in malignancy patients are malignancy-related. They are different from those in healthy people as well as patients with autoimmune disease. Further efforts should be made to identify the target antigens as well as their biological role and clinical significance.