By assaying lactate dehydrogenase and malondialdehyde leakage from LLC-PK1 cells in culture, a study was conducted to clarify whether flavonoid compounds ameliorate renal cellular injury. The cells were cultured with various concentrations of samples under routine conditions. The results demonstrated that baicalin, cirsimaritin, 6-hydroxyluteolin, luteolin, plantaginin, rhoifolin, sorbarin, afzelin, hyperin, isoquercitrin, isorhamnetin, kaempferitrin, kaempferol-7-glucoside, oxyayanin A, quercetin, quercitrin, rhamnetin and rutin exerted marked protective effects on the cells, whereas acacetin, apigenin, apiin, cirsilineol, genkwanin, pectolinarin and tetramethylquercitin had virtually no effect. In the light of these findings, we propose that the general capability of these compounds is largely decided by the number and position of phenolic hydroxyl groups linked to the structural backbone.