Objective:To investigate the prognostic correlation between mitochondrial DNA(mtDNA)content and colorectal cancer. Methods:Clinical and pathological data were collected from 117 patients with colorectal cancer. RT-qPCR was used to determine the mtDNA content of cancer tissues and paracancerous tissues of patients,and the correlation between mtDNA content and various prognostic indicators was investigated. Receiver operating characteristic(ROC)curves were plotted,and the cut-off value was determined to distinguish patients,and disease free survival(DFS)curves were plotted accordingly. Univariate and multivariate Cox regression analyses were conducted to explore the risk factors related to postoperative DFS. Results:There was no significant difference in mtDNA content between cancer tissues and paracancerous tissues(P=0.432);low mtDNA content was associated with tumor location in the colon,poor differentiation,advanced TNM stage,and lymph node metastasis(P < 0.05). The ROC curve indicated a cut-off value of 500.699 for mtDNA content. Univariate and multivariate Cox analyses showed that mtDNA content lower than 500.699 (HR=4.285,95%CI:1.938-9.475)and poorly differentiated tumors(HR=2.886,95%CI:1.428-5.835)were independent risk factors associated with DFS. Conclusion:In patients with colorectal cancer,tissue mtDNA content is associated with clinical and pathological characteristics,and low mtDNA content is an independent risk factor for patient prognosis.