〔Abstract〕 Objective To explore the relationship between the expression of macrophage-derived Bruton′s tyrosine kinase(BTK) with renal function in the kidneys of patients with diabetic nephropathy(DN). Methods 49 patients with DN diagnosed by renal biopsy were collected as the DN group. 18 normal human serum and 18 normal kidney tissues adjacent to the cancer in patients with kidney cancer were collected as a control group. Clinical indicators of all participants were collected. The expression of interleukin(IL)-1β, tumor necrosis factor(TNF)-α and monocyte chemotactic protein(MCP)-1 in the serum of the control group and the DN group was detected by ELISA. The expression of TNF-α, CD68, BTK and p-BTK in renal tissues of the control group and the DN group was detected by immunohistochemistry. Laser confocal was performed to observe the co-expression of inducible carbon monoxide synthase(iNOS) and p-BTK in kidney tissue macrophages in the control group and the DN group.Results Compared with the control group,the levels of Hb A1 c,blood pressure,creatinine,urea nitrogen and uric acid in DN group significantly increased,and the levels of serum inflammatory cytokines TNF-α,IL-1β and MCP-1 significantly increased. Compared with the control group,the expression of TNF-α,the infiltration of macrophages and the activation of BTK significantly increased in DN group,and the expressions of iN OS and p-BTK in renal macrophages also increased. In DN group,BTK and p-BTK expression were positively correlated with 24 hour urinary protein,serum creatinine and blood urea nitrogen,and negatively correlated with estimated glomerular filtration rate( e GFR). Conclusion The activation of BTK in renal macrophages is increased in DN patients and is correlated with renal function progression.