Aim: To observe the effects of Ginkgo biloba extract (EGb) on the hypertrophy of mesangial cells and the accumulation of extracellular matrix (ECM) in mesangial cells. Methods: Cultured mesangial cells were allotted into 7 groups: normal group, solvent control group, high glucose group, low dose of EGb group, moderate dose of EGb group, high dose of EGb group, and captopril group. Activities of cell antioxidases, S phase percentage and G0/G1 phase percentage, collagen Ⅳ and laminin, Smad2/3 and Smad7, TGF-β1, Ma were measured by different methods. Results: For EGb-treated groups, when compared with high glucose group, the cell percentage of S phase was raised and the percentage of G0/G1 was lowered. The intensity of oxidative stress was weakened. The expression of Smad2/3 was greatly decreased and Smad7 was increased. Collagen Ⅳ, laminin and TGF-β1 Ma were also reduced. Conclusion: EGb can suppress cell hypertrophy and the accumulation of ECM in rat mesangial cells, which means it could play a vital role in the delay of glomerulosclerosis in diabetic nephropathy.