Abstract: Objective To evaluate the expression and discussion on high mobility group protein ( HMGB1)/toll like receptor 4 (TLR4) and NF-?B possible role in the signaling pathway in preeclampsia. Methods 10 cases of patients with mild preeclampsia(MP), 20 patients with severe preeclampsia(SP) and 30 cases of normal pregnancy as a research object in the same period.To navigate the qualitative expression of the HMGB1,TLR4,NF-?Bp65 protein in placenta tissue using Immunohistochemical staining.Levels of HMGB1,TLR4,NF-?Bp65 in blood serum were measured by ELISA. Result (1) Immunohistochemistry showed that the expression of HMGB1,TLR4,NF-?Bp65 were stronger than that of control group in the placental of preeclampsia（P＜0.05);But HMGB1,TLR4,NF-?Bp65 in placenta of patients with severe preeclampsia and mild preeclampsia comparison of the differences is no statistically significant（P＞0.05).(2) Levels of HMGB1、TLR4、NF-?Bp65 in women with preeclampsia significantly higher than control group( P<0.05); Levels of HMGB1、TLR4、NF-?Bp65 in women with severe preeclampsia higher than with mild preeclampsia (P＜0.05).Conclusion HMGB1,TLR4 and NF-?Bp65 were up-expressed in the placenta tissue and serum in patients with preeclampsia, which indicated that HMGB1,TLR4 and NF-?Bp65 may play an important role in the development of preeclampsia.