线粒体是细胞代谢过程中最重要的细胞器之一，其基因组具有易突变、缺乏损伤修复机制等特点。在肿瘤发生发展的过程中，线粒体DNA（mitochondrial DNA，mtDNA）的突变及拷贝数变异都起到了重要的作用。近年来的研究发现，多种肿瘤疾病中都存在mtDNA的突变及拷贝数变异，而针对肿瘤组织mtDNA，尤其是患者体液中游离mtDNA的检测也有可能成为提示肿瘤疾病的重要方法。本文旨在总结线粒体基因组突变及拷贝数变异与肿瘤疾病及其诊断的相关性，并对其作为肿瘤标志物的研究进展进行综述，从而为肿瘤疾病的临床诊断提供参考。

Mitochondria are one of the most important organelles in cellular metabolism， and their genomes are prone to mutations and lack damage repair mechanisms. Mitochondrial DNA （mtDNA） mutations and copy number variations play important roles in the occurrence and development of tumors. In recent years， research has found that mtDNA mutations and copy number variations exist in various tumor diseases， and the detection of mtDNA in tumor tissues， especially cell-free mitochondrial DNA in patient fluids， may also serve as important means to indicate tumor diseases. This article aims to summarize and to review the correlation between mitochondrial genome mutations and copy number variations with tumor diseases and their diagnosis， as well as the research progress as tumor biomarkers， in order to provide reference for the clinical diagnosis of tumor diseases.