Objective:To investigate the quality of sleep in primary Sj?gren′s syndrome (pSS) patients and its impact on clinical features.Methods:One hundred patients with pSS who were hospitalized in the Department of Rheumatology of the Second Hospital of Shanxi Medical University from January 2019 to April 2021 were included into this study. Pittsburgh sleep quality index (PSQI), fatigue severity score (FSS), Euro QOL five dimensions questionnaire (EQ-5D), beck depression inventory second edition (BDⅠ-Ⅱ) and visual analog scale (VAS) were used to assess patients' symptoms and overall condition. The data was statistically managed and compared by χ2 test, independent sample t test, Mann-Whitney U test, and Logistic regression. Results:The prevalence of sleep disorders in pSS patients was 42.0%(42/100). The prevalence of sleep disturbance in pSS patients without depression was 28.8%(17/59). The EQ-5D[0.66(0.59, 0.76)] and Eur-opean league against rheumatism Sj?gren's syndrome disease activity index (ESSDAI) scores [1.0(0.0, 3.0)] were lower in patients in the sleep-disordered group than in those [0.76(0.71, 1.20) and 2.5(1.0, 4.0)] who slept well [ Z=3.07, P=0.012; Z=3.18, P=0.011], respectively. The European league against rheumatism Sj?gren's syndrome patients report index (ESSPRI) scores [6.2(4.8, 7.9)], VAS levels in overall dry eyes [60.0(21.4, 82.1)], anxiety [11.0(2.9, 43.0)], overall physician global assessment (PGA) [46.0(18.0, 65.0)], fatigue severity scale (FSS) [4.34(3.01, 5.61)], and BDⅠ-Ⅱ [15.1(7.3, 22.4)] in patients with sleep disorder were higher than those [4.1(2.8, 5.3), 40.0(7.0, 70.3), 2.3(0.0, 18.0), 11.0(0.0, 52.0), 2.45(1.65, 4.40), and 7.4(4.3, 12.8)] of the normal sleep group [ Z=2.03, P=0.043; Z=2.04, P=0.042; Z=2.19, P=0.031; Z=3.00, P=0.015; Z=3.43, P=0.001; Z=3.12, P=0.003]. The sleep-disordered group had higher levels of lymphocyte count (2.0±1.5)×10 9/L and erythrocyte sedimentation rate (ESR) (46±20) mm/1 h respectively when compared with (1.4±1.3)×10 9/L and (38±17) mm/1 h in the good sleep group ( t=2.00, P=0.048; t=2.04, P=0.044). PSQI scores were negatively correlated with immunoglobulin (Ig)G ( r=-0.20, P=0.012) and ESSDAI ( r=-0.26, P=0.004), while positively correlated with FSS( r=0.38, P=0.001), BDⅠ~Ⅱ ( r=0.47, P=0.014), ESSPRI ( r=0.46, P=0.001), white blood cell count ( r=0.28, P=0.013) or neutrophil count ( r=0.26, P=0.009). The results of multifactorial analysis suggested that leukocytopenia [ OR(95% CI)=0.245(0.065, 0.692), P=0.005] was one of the risk factors for sleep disorders. Conclusion:Sleep disorders in pSS patients affects the patients' disease prognosis and activity index by affecting the patients' somatic symptoms, psychological profile and immune function. Active clinical multidis-ciplinary interventions for pSS patients are necessary, not only for better assisting physicians in the manage-ment of chronic diseases, but also for better help patients recovery of their physical and mental health.