【Abstract】 Objective To investigate PO and HPA expression level and clinic significance of patients with PSS in order to provide basis for clinic treatment. Methods 60 patients with PSS in our hospital from February 2014 to February 2016 were selected as observation group. 60 healthy people were chosen as control group. TPO and HPA expression level and other clinic indexes, including WBC, RBC, PLT, HB, ESR, CRP, ANA, anti SSA antibody, anti SSB antibody, G(IgG), A(IgA), M(IgM), 3(C3), 4(C4) and CIC were observed. Results Difference among thrombopenia group, used thrombopenia group and platelet normal group was not statisticly significant (P>005). TPO expression level of observation group was obviously higher than that of control group (P<005). HPA of the two groups had no statistic significance (P>005). TPO of thrombopenia group, used thrombopenia group and platelet normal group were obviously higher than that of control group (P<005). HPA of thrombopenia group, used thrombopenia group and platelet normal group had no difference from that of control group (P>005). lgA and CIC of platelet normal group were higher than thrombopenia group and used thrombopenia group (P<005). WBC, RBC, ESR, CRP、lgG, lgM, C3, C4, SSAAb, SSBAb, HB and lgE of three groups had no statistic significance (P>005). The difference of CIC between thrombopenia group and used thrombopenia group had no statistic significance (P>005). The difference of CIC between thrombopenia group and platelet normal group had statistic significance (P<005). The difference of lgA between thrombopenia group and used thrombopenia group had no statistic significance (P>005). The difference of lgA between platelet normal group, thrombopenia group and used thrombopenia group had statistic significance (P<005). TPO had no correlation with clinic indexes (P>005). HPA had no correlation with clinic indexes (P>005). HB and anti SSAAb were negatively correlated（r=0335，P<005）. HB and anti SSBAb were negatively correlated （r=0290，P<005）. anti SSBAb, C4 and CIC were positively correlated （r=0289，r=0312，P<005）. PLT and IgA were positively correlated（r=0426，P<005）. Conclusion The present study shows that TPO and HPA expression level may had no relation with PPS. The aetiological agent of PSS may caused by immune disorders.