In WKY rats, administration of a small dose of anti-glomerular basement membrane antibody induces severe crescentic glomerulonephritis, which is characterized by infiltration of CD8-positive lymphocytes and monocytes/macrophages into the glomeruli with crescent formation. In this study, the involvement of the complement system was examined in the induction of this model. To deplete complement, cobra venom factor (CVF) was used. By a single injection with CVF at 24 h prior to the induction of this model, plasma C3 level from days 0-2 was less than 10% compared with pre-injection of CVF. Complement was almost depleted in the early phase of this model. No significant differences were observed in proteinuria and the frequency of glomeruli associated with the extracapillary crescentic lesions between the CVF-treated group and the control group. In addition, the number of monocytes/macrophages and CD8-positive lymphocyte infiltration into the glomeruli showed no significant differences between both groups. These results indicate that the possibility of complement system involvement is considered low in the induction of this model.