Abstract: The detction of serum anti-polytene chromosomes of Drosophila melanogaster antibodies（AchrA） by indirect immunofluorescence assay （IIF） is described in this paper. Sixteen of 44 patients with systemic lupus erythematous （SLE） tested were positive for AchrA, whereas none of 151 nomal svbjects and other rheumatic disease patients （ORD_S） were positive. In addition, positive ANA was present in 33 of 44 SLE patients and 39 of 109 ORD_S patients. The results suggest that AchrA is the more specific antibodies than ANA in SLE and may provide a new aid for diagnosing SLE.