【Abstract】 Objective To investigate the relationship between mitochondrial DNA (mtDNA) Dloop gene polymorphism and renal clear cell carcinoma.Methods 63 patients with renal clear cell carcinoma treated in our hospital from March 2014 to February 2017 were selected as the observation group. 70 healthy volunteers were selected as control group. The mtDNA Dloop region was amplified and sequenced, and the difference of mtDNAloop polymorphism between the two groups was compared. Results 135 polymorphic loci were found in the mtDNA Dloop regions in the observation group and the control group, of which the frequency of the 9 loci was＞5%. The genotype frequency distribution of the two groups of 262 loci was consistent with HardyWenberg's law. The frequency of TT genotype and allele T in the observation group was 1905% and 3889%, which was significantly higher than that in the control group (P＜005). There were no statistically significant differences in the polymorphism of mtDNA Dloop 262 loci between patients with different gender, age, pathological grade and clinical stage (P＞005). The median survival time of patients with CC genotype and CT genotype was 4040 months and 4020 months, which was significantly higher than that of TT genotype patients 3481 months, and the difference was statistically significant (P＜005). Conclusion In patients with clear cell renal cell carcinoma, the frequency of allele T in mtDNA Dloop region 262 loci is obviously higher, but it has nothing to do with clinical pathological features. Whether it is relate to patient prognosis, it needs further study.