MiRNAs can function as oncogenes or tumor suppressor genes. The abnormal expression of miRNAs leads to tumor malignant phenotypes, such as cell proliferation, apoptosis, invasion and metastasis, through which it is involved in the process of tumor initiation, progression and transcriptional regulation network. Therefore, it is important to clarify the mechanism of miRNA involved in the process of tumor initiation and progression. MiRNA regulation mechanism in tumor initiation and progression includes one-to-many and many-to-one regulation between TFto- miRNA and miRNA-to-target gene, which increases the complexity of miRNA regulation, thus affecting the biological behavior of the tumor, The expression and activity of Drosha and Dicer in the process of miRNA affect the synthesis of mature miRNA and involve in the process of tumor initiation and progression; ceRNA may bind with miRNA by competing with miRNA targeting genes and affect biological function of miRNA as miRNA inhibitor. Therefore the abnormal expression and structure of ceRNA is an important molecular mechanism of tumor initiation and progression. This complicated regulation network comprised by multi-dimensional regulation model and specific regulation of tumor initiation and progression provides impetus to exploring the functional restoration of miRNA as a novel target for cancer diagnosis and therapy.