With the rapid development of modern society, the incidence of human tumors has been increased year by year, posing a serious threat to human health. There are more and more researches on tumors, among which there are many studies on mitochondrial DNA(mtDNA) and tumor. Especially in recent years, the research on mtDNA and tumor has gradually become the focus of tumor research. MtDNA research involves point mutation, fragment deletion, content change and so on. This paper comprehensively collated the relevant research on mtDNA content in tumors, reviewed the relevant research literature on mtDNA content in different tumors at home and abroad in past 10 years, found out the research methods and relevant data and data obtained for induction, analysis and summary. It is found that there are many studies on mtDNA content in tumors, and the types of tumors studied are diverse, involving the occurrence, development, treatment and prognosis of different tumors. The results of different studies are not the same, or even the opposite. However, a large number of studies have shown that mtDNA content changes in the occurrence and development of tumors, and mtDNA content changes have  impacts on the occurrence, development, treatment and prognosis of tumors and so on. mtDNA content changes play a different role in different tumors and at different stages of tumors, and the mechanisms are diverse. These research data provide theoretical reference for the related studies of tumor  mtDNA content in the future, and it is expected to make contributions to the diagnosis and treatment of tumor.