OBJECTIVE To compare the isolation effects and yields of rat kidney cells by three different digestion methods (collagenase, trypsinase, and the two step digestion method), the yields, proliferation rate, and LDH leakage in two different media (MEM and RPMI1640 media) in rats in two different ages (suckling and adult) . METHODS The renal cortex from the suckling and the adult rat group was digested by three different methods, respectively, and the suspension was separately cultured in MEM and RPMI1640 media. After 48 hours, the cells were digested and counted to calculate the yields, and the proliferation rate between 24h and 48h was examined by MTT examination, and the leakage of LDH in the media was measured by biochemical analyzer every day for 7 days. RESULTS The yields of kidney cells by collagenase and the two-step method were significantly higher than by trypsinase method (P < 0.01), the suckling group were significantly higher than the adult group. The isolation effect of the two-step method was better than the collagenase method. The yields, proliferation rate, and LDH leakage of cells in MEM and RPMI1640 media had no significant difference. CONCLUSIONS The two-step digestion method was the most appropriate method for the preparation of kidney cells. Both MEM and RPMI1640 media were suitable for the culture of kidney cells. The suckling rat was proper than the adult for kidney cell preparation.