The invention discloses a composition for treating diabetic nephropathy, wherein the composition is prepared from the following raw medicines: 0.5-1.5g of levocarnitine, 20-40g of astragalus membranaceus, 20-40g of bighead atractylodes rhizome, 10-30g of the root of red-rooted salvia, 10-30g of cortex cinnamomi, 5-25g of parasitic loranthus, 5-25g of ootheca mantidis, 5-25g of flatstem milkvetch seed, 5-25g of poria cocos, 5-25g of forged fossil fragments, 5-25g of forged concha ostreae, 2-15g of red flower and 2-10g of rhizoma alismatis. In use, the composition mainly comprises qi-tonifying medicine, interior-warming medicine, blood-activating blood and stasis-dissolving medicine, heat-clearing medicine, water-disinhibiting and damp-percolating medicine and is supported by western medicine components, so that therapeutic principle and method for tonifying deficiency and tonifying qi, activating blood and dissolving stasis and clearing heat and promoting dieresis are determined; finally, the unexpected technical effect is achieved.