ABSTRACT: Introduction & Objective: Cisplatin is a potent antineoplastic drug. The beneficial effects of the drug are limited by its nephrotoxicity. The purpose of this study is to introduce sterological meothds (Estimation of mean glomerular volume) to determine the toxicity of drug & examine the Galium aparine (a traditional herbal plant) as a protective agent. Materials & Methods: This experimental study was done in histology department in Ahwaz University of medical sciences in 1380. 70 Spraque–Dwally male rats were iselected randomly and divided into 7 groups as below: two control groups (one for drug & one for plant), five experimental groups one treated by acute dose of drug (7.5 mg/kg, IP) and other groups treated with 4 doses of hydroalcholic extract of plants (4, 8, 16, 32 mg/kg) half an hour before receiving drug orally. Animals were sacrified 96 hour after receiving the drugs and their right kidneys were processed for stereological assessment based on cavalier method. Statistical analysis of data from calculation of mean glomerular volume was done by ANOVA and two sided-dunet test, using SPSS software. Results: The results based on cavalier method, showed an increase in mean glomerular volume in all the groups that were treated with drug, whereas lower grade of glomerulomegaly was seen in those groups which received higher doses (16 & 32 mg/kg) of plant’s extract (p<0.05). Conclusion: Nephrotoxicity induced by cisplatin was even observed in quantitative parameters of kidney (e.g. increasing the mean glomerular volume) but by using Galim apain’s extract this side effect can be reduced significantly. Moreover stereological techniques are valuable tools for studying the drug effects in all organs of the body.