Objective To investigate the clinical value of multi-slice spiral CT (MSCT) perfusion in evaluation of renal function in patients with diabetic nephropathy (DN). Methods 31 cases of patients with clinically diagnosed DN and 26 normal volunteers were selected as the study subjects. All of them underwent bilateral renal perfusion scan with 64 slice spiral CT. The relationship between renal cortical perfusion parameters and clinical examination indicators in the two groups was compared. The changes in clinical examination indicators before and after perfusion scan were analyzed. Results The renal blood flow (BF), renal blood volume (BV) and renal permeability surface (PS) in DN group were significantly lower than those in control group. The mean transit time (MTT) of renal contrast agent was significantly longer than that of control group (P<0.05); BF, BV, MTT, PS and microalbumin, 24h urinary protein quantitation, creatinine and fasting blood glucose were correlated. BF and BV had no correlation (P<0.05). Conclusion MSCT renal perfusion parameters and microalbumin, 24h urinary protein quantitation and fasting blood glucose have certain correlation, which can be used for evaluation of renal function damage in patients with DN.