Objective To investigate the clinical value of color doppler flow imaging (CDFI) and super microvascular imaging (SMI) on renal perfusion changes in patients with chronic kidney disease (CKD).Methods CDFI and SMI were used to observe the bilateral renal perfusion in normal subjects (control group) and patients with CKD1-5 stage (case group), respectively, and to test the evaluation effect of CDFI and SMI on renal perfusion changes in CKD patients by grading the renal blood flow distribution, and to compare the ability of SMI to show the renal vasculature at all levels. Spearman analysis was also used to correlate the CDFI and SMI perfusion grading with the first three clinical stages of CKD.Results 1.The differences in CDFI and SMI renal perfusion grading between the control group and CKD1 and CKD2 stages were not statistically significant (P>0.01). 2. In CDFI renal perfusion imaging, the changes in renal perfusion in the first three stages of CKD were not significant, and the differences were not statistically significant (P>0.01); the differences between CKD4-5 stages and the first three stages were significant, and the differences were statistically significant (P<0.01). 3. The difference between CKD stage 3 and CKD1, CKD stage 2 and CKD stage 4-5 in SMI renal perfusion imaging was significant (P<0.01), and the difference between CKD stage 4-5 and the first three stages was significant (P<0.01). 4. With the higher clinical stage of CKD, the renal perfusion grade of both SMI and CDFI decreased, and the renal perfusion grade of SMI in each stage was higher than that of CDFI. while the flow grading of high occupancy ratio detected by SMI was higher than that of CDFI in each group,and the difference was statistically significant (P<0.05), and the SMI showed a clearer picture of the arcuate and interlobular arteries in particular. 5. There was a strong correlation between SMI renal perfusion grading and CKD clinical stage (Rs -0.657, P < 0.01); there was a moderate correlation between CDFI renal perfusion grading and CKD clinical stage (Rs -0.419, P < 0.01).Conclusion SMI can be used as an important imaging method to evaluate the renal perfusion changes in CKD, which can effectively assist in the diagnosis, treatment and prognosis of CKD patients, and has important clinical application valueand it is safe and reliable with strong follow-up. It is worthy of clinical promotion and application.