Abstract: Objective To study the influence of low density lipoprotein on phenotype change of the cultured rat glomerular mesangial cells(MCs).Methods The rat glomerular mesangial cells were cultured for seven days in low density lipoprotein(0,25,50,100,150μg/ml).MCs proliferation was measured under MTT assay.Morphological changes were observed by electronic microcopy.α-SMA、CTGF were examined by immunohistochemistry stain and Western blot.Results Glomerular mesangial cells cultured in low density lipoprotein showed obvious morphlogic changes,including elongated shape and the appearance of muscle actin.The expression amount of α-SMA、CTGF enhanced by using immunohistochemistry stain and Western blot.Conclusion Low density lipoprotein can lead to the phenotypic change of glomerular mesangial cells and have much something with fibrosis of the kidney.