Objective To investigate the expression of FcγRⅡb on peripheral B cells and its clinical significance in primary Sj(o)gren's syndrome (pSS).Methods FcγRⅡb expression on peripheral B cells from 19 pSS patients and 15 healthy controls was examined by flow cytometry.The levels of serum anti-SSA and SSB antibodies were determined using enzyme-linked immunosorbent assay (ELISA).Data were analyzed with t test,one-way ANOVA,SNK-q test and Pearson's correlation test.Results The percentage of memory CD19+CD27+ B cell subpopulation was significantly lower in pSS patients [ (20.8±2.7)％] when compared to normal controls [(37.8±2.2)％ ](t=-4.002,P＜0.01).The level of expression of FcγRⅡb in active pSS memory CD19+CD27+ B cells [ MFI(74±8)] was significantly reduced when compared to inactive [ MFI( 132±11)] and normal controls [ MFI (139±12)] (F=10.699,P＜0.01).The level of expression of FcγRⅡb on memory CD19+CD27+ B cells from pSS patients was inversely correlated with Sj(o)gren's syndrome disease activity index (SSDAI) (r=-0.744,P=0.0003 ).pSS patients with the serum anti-SSA/SSB antibodies positive group [ MFI(75+3),(48±7)] displayed a lower expression of FcγRⅡb on memory CD19+CD27+ B cell than in patients with the serum anti-SSA/SSB antibodies negative group [MFI( 122±11),(108±9)] (t=-4.336 and -3.776 respectively,the P value of both tests were less than 0.01).The level of expression of FcγRⅡb in the memory CD19+CD27+ B cells of patients with active pSS was inversely correlated with anti-SSA antibody titers (r=-0.685,P=0.014).Conclusion The expression of FcγRⅡb on peripheral memory B cells from active pSS patients is inversely correlated with SSDAI and is also inversely associated with anti-SSA antibody levels.Decreased expression of FcγRⅡb might play an important role in the pathogenesis of pSS.