To examine the effect of multi-glycoside of Tripterygium wilfordii Hook. f. (GTW) on proteinuria and acute glomerular immune lesion in experimental mesangial proliferative glomerulonephritis (MsPGN) induced by anti-Thy1.1 monoclonal antibody (mAb) 1-22-3. The reversible model of MsPGN with anti-Thy1.1 mAb 1-22-3 was established. After 7 days of oral treatment with GTW (100 mg/kg per day) and vehicle (distilled water, 5 ml/kg per day), its effects on proteinuria, renal functions, mesangial morphological change, glomerular macrophage accumulation, and mRNA expressions of cytokines (PDGF-BB and MCP-1) were evaluated by light microscope (LM), immunofluorescence (IF), and reverse transcription polymerase chain reaction (RT-PCR). It was found that GTW ameliorated proteinuria (on day 3 and day 7), mesangial proliferation (total cell number, matrix expansion, α-smooth muscle actin expression, and collagen type Ⅰ expression) and macrophage accumulation (ED3~+) in experimental MsPGN. In addition, GTW significantly suppressed the increased mRNA expressions for MCP-1 (67.6% to control group, P<0.01) together with the tendency to reduce the expression of PDGF (24.44% to control group) on day 7. It is concluded that GTW can not only decrease proteinuria, but also ameliorate acute mesangial alterations and glomerular activated macrophage accumulation probably by reduction of cytokines. These data indicate that GTW is an effective agent for early MsPGN. To examine the effect of multi-glycoside of Tripterygium wilfordii Hook. F. (GTW) on proteinuria and acute glomerular immune lesion in experimental mesangial proliferative glomerulonephritis (MsPGN) induced by anti-Thy1.1 monoclonal antibody (mAb) 1-22-3 . The reversible model of MsPGN with anti-Thy 1.1 mAb 1-22-3 was established. After 7 days of oral treatment with GTW (100 mg / kg per day) and vehicle (distilled water, 5 ml / kg per day) , its effects on proteinuria, renal functions, mesangial morphological change, glomerular macrophage accumulation, and mRNA expressions of cytokines (PDGF-BB and MCP-1) were evaluated by light microscope (LM), immunofluorescence (IF), and reverse transcription polymerase chain It was found that GTW ameliorated proteinuria (on day 3 and day 7), mesangial proliferation (total cell number, matrix expansion, α-smooth muscle actin expression, and collagen type Ⅰ expression) and macrophage accumulation ( ED3 ~ +) in experimental MsPGN. In addit ion, GTW significantly suppressed the increased mRNA expressions for MCP-1 (67.6% to control group, P <0.01) with the tendency to reduce the expression of PDGF (24.44% to control group) on day 7. It is said that GTW can not only decrease proteinuria, but also ameliorate acute mesangial alterations and glomerular activated macrophage accumulation probably by reduction of cytokines. These data indicate that GTW is an effective agent for early MsPGN.