Objective: To observe expression of lymphotoxin beta receptor (LTβR) molecule on monocytes from peripheral blood of systemic lupus erythematosus(SLE) patients, and to explore regulating factors. Methods:Peripheral blood mononeuclear cells(PBMCs) from the patients and controls were separated, and then LTβR molecule expression was detected by FACS. Monocyte were separated from PBMC by the immunomagnetic beads, and then the mRNA level of LTβR was detected by RT-PCR. Besides, the changes of LTβR expression on the monocyte cell lines(U937 and THP1) and nomal peripheral blood monocyte were investigated after stimulation with LPS,PMA or DEX in vitro. Results:The PBMCs from SLE patients expressed abnormaly high levels of LTβR molecule, which did not express on the PBMCs from normal controls. In cell culture in vitro, DEX up-regulated the espression of LTβR on U937 cell, but did not on THP1 cell and normal peripheral blood monocyte. In U937 and THP1 cell cultures, LTβR expression on cell membrane displayed a temporary decrease,but the LTβR mRNA did not show any changes after treatment with PMA;while no changes were found in LTβR expression on normal peripheral blood monocyte after PMA treatment. Neither the U937 and THP1 cell lines, nor the normal peripheral blood monocyte, did not display any changes in LTβR expression after LPS treatment. Conclusion:The LTβR molecule highly expresses on peripheral blood monocyte from SLE patient, and this abnormal expression may be not related to the active of monocyte or the treatment of glucocorticoid medicine. On the other hand, DEX may be a factor that can influence this molecule expression of monocyte in an earlier stage of development.