Previous studies suggested a pathological role for the death decoy receptor 3 (DcR3) in systemic lupus erythematosus (SLE) and rheumatic arthritis (RA). Herein, the expression of DcR3 in primary Sjögren's syndrome (pSS) and the relationship with clinical characteristics were investigated. The serum DcR3 levels of pSS patients and healthy controls were measured by ELISA. Pearson's correlation analysis was used to evaluate the relationship between the DcR3 levels with the clinical characterstics of pSS patients. Additionally, the DcR3 expression in salivary glands of pSS patients was investigated by the immunohistochemistry method. The serum DcR3 expression in pSS patients was significantly higher than healthy controls (p < 0.001), especially in new onset pSS patients (p = 0.036). Moreover, Pearson's correlation analysis show that DcR3 levels were positively correlated with age (p = 0.013), platelet (PLT) (p = 0.002), hemoglobin (Hb) (p = 0.004), Sjögren's syndrome disease damage activity index (SSDAI) score (p = 0.005), Sjögren's syndrome disease damage index (SSDDI) score (p < 0.001) and EULAR Sjögren's syndrome disease activity index (ESSDAI) score (p = 0.010). Furthermore, the DcR3 levels were significantly lower when the pSS patients were treated with the disease-modifying anti-rheumatic drugs. At last, DcR3 expression in salivary glands of pSS patients was significantly higher than healthy controls. The DcR3 expression was significantly elevated in the pSS patients and positively correlated with the clinical characteristics, and it might be an important factor involved in the progression of pSS patients and could be a potential therapeutic target.