Objective：To observe the effect of extract of Radix et Rhizoma Salviae Miltiorrhizae on transforming growth factor-β1(TGF-β1)and p38 mitogen-activated protein kinase(p38MAPK)in rats with mesangial proliferative glomerulonephritis(MsPGN).Methods：A total of 46 SD rats were divided into the normal group，the valsartan group，the model group and the extract of Radix et Rhizoma Salviae Miltiorrhizae group.The rat models with MsPGN were established in all groups except the normal group.The extract of Radix et Rhizoma Salviae Miltiorrhizae group was given 5 g/(kg·d)of Radix et Rhizoma Salviae Miltiorrhizae by gavage；the valsartan group was given 0.01 g/(kg·d)of valsartan dissolved in warm water by gavage，and the model group and the normal group were daily given the same amount of warm water by gavage.After 12-week gavage，all rats were sacrificed.The protein expression of TGF-β1 and p38MAPK in the kidney tissue of rats was detected by Western blot，and the mRNA expression of TGF- β1 and p38MAPK was detected by RT-PCR.Results：Compared with those in the normal group，the level of 24-hour urine protein and the relative protein expression as well as the mRNA expression of TGF-β1 and p38MAPK in rats in the model group were significantly increased(P ＜ 0.05)；compared with that in the model group，the levels of 24-hour urine protein in the valsartan group and the extract of Radix et Rhizoma Salviae Miltiorrhizae group after medication for six weeks and 12 weeks respectively were significantly decreased(P＜ 0.05)；the relative protein expression as well as the mRNA expression of TGF-β1 and p38MAPK in the valsartan group and the extract of Radix et Rhizoma Salviae Miltiorrhizae group were significantly decreased(P ＜ 0.05)；compared with that in the valsartan group，the mRNA expression of TGF-β1 and p38MAPK in the extract of Radix et Rhizoma Salviae Miltiorrhizae group was decreased(P＜ 0.05).Conclusion：The renal protection of extract of Radix et Rhizoma Salviae Miltiorrhizae may be achieved by down-regulating the levels of protein and mRNA of TGF-β1 and p38MAPKand inhibiting the activation of TGF-β1/p38MAPKsignaling pathways.