Objectives: Obesity induces abnormal lipid metabolism, leading to metabolic diseases. Abnormal lipid metabolism has been reported as an independent risk factor for renal injury, and synergistic effects in unilateral kidney promote changes in gene expression associated with renal injury. However, the correlation between obesity-induced lipid metabolism abnormalities and renal damage in a single kidney has not been elucidated. Methods: To determine lipid metabolism and renal function in unilateral kidney with obese mice, mice were randomized to undergo unilateral nephrectomy and fed standard or high-fat diets for 13 weeks. There were four groups; normal diet (ND), high-fat diet (HD), normal diet and received uninephrectomy (NDU), and high-fat diet and received uninephrectomy (HDU). In vitro, podocytes were treated with cholesterol ester for 24 hours, and cell function and protein expression were confirmed. Results: In unilateral kidney, kidney function decreased regardless of diet, but lipid accumulation and renal injury were promoted in kidney of HDU group compared to HD group. As a result of protein analysis, it was confirmed that HDU group had reduced expression of proteins involved in fatty acid oxidation and efflux, increased expression of cholesterol synthesis-related proteins, abnormal autophage-related protein expression, mitochondria damage, and increased fibronectin. In podocytes, cholesteryl ester causes cellular dysfunction, lipid accumulation and abnormal lipid metabolism, leading to cell damage by lipotoxicity. Conclusions: Long-term high-fat diet induces abnormalities of lipid metabolism in a unilateral kidney model, leading to increased lipid accumulation and accelerates deterioration of kidney function with lipotoxicity.