Objective:To explore the diagnostic significance of pentraxin 3(PTX3) in patients with Sjogren’s syndrome(SS). Methods:Plasma from 52 patients with SS and 15 healthy volunteers was detected for the level of PTX3 by ELISA. Correlation between PTX3 and clinical indexes of the patients with SS was analyzed. Results:Level of PTX3 in SS patients especially with tubular damage patients[(1.492 ± 0.018)ng/mL]was significantly higher than that in the control group[(1.403 ± 0.019)ng/mL](P < 0.01),and the plasma level of PTX3 [(1.573 ± 0.019)ng/mL]of patients(n=31)with renal tubular dysfunction(including abnormal urine acidification function,urine NAG and abnormal urinary β2-microglobulin)was significantly higher than that in patients without tubular damage[(1.418 ± 0.003)ng/mL](P < 0.01). Plasma PTX3 was negatively correlated with TA and NH4+ in the urine of SS with tubular damage(P < 0.05). However,there was no correlation between ESR,CRP,IgG,IgA,IgM,SSA,SSB,and RF. Efficacy of PTX3 in the diagnosis of renal tubular dysfunction in patients with SS was equivalent to that of urinary β2-microglobulin. The area under ROC curve of PTX3 was 0.702(95%CI:0.593~0.811),which had no difference compared with urinary β2-microglobulin[AUC:0.705,95%CI:0.567~0.843]. Conclusion:Plasma PTX3 could be a useful marker of tubular damage in SS patients.