Abstract: An indirect immunofluorescence technique for the detection of ASDA has been developep by the writer and used in screening 34 patients with rheumatoid arthritis, 15 with SJögren’s syndrome-rheumatoid arthritis and 15 with primary SJögren’s syndrome, 63 with other connective tissue diseases, 9 with other diseases and 40 normal controls. The incidence of ASDA in patients with SJögren’s syndrome-rheumatoid arthritis（66.67%） or rheumatoid arthritis（32.35%） was significantly higher than that in normal controls（P＜0.001）. In patients with primary SJögren’s syndrome and other CTDs, non-CTDs, no ASDA was found. However, in patients with SJögern’s syndrome-rheumatoid arthritis or rheumatoid arthritis alone, ASDA was not correlated with age, sex, disease duration or serological findings. The result suggests that the detection of serum ASDA might be useful in the differentiation of SJögren’s syndrome with rheumatoid arthritis from primary SJögren’s syndrome with arthralgia and/or arthritis.