miRNAs are a class of endogenous non coding, single stranded small RNAs, which regulate the expression of tumor suppressor genes and oncogenes and involve in almost all of the tumor-related processes. miRNA-29c, acting as a tumor suppressor of miRNA, has low expression in many solid malignancies such as nasopharyngeal carcinoma, glioma, gastric cancer, hepatocellular carcinoma, bladder cancer, esophageal cancer, breast cancer, colon cancer and so on. It relates with cancerous proliferation, apoptosis, invasion and metastasis. miRNA-29c directly inhibits the transcription of the target gene encoding protein and down regulates the expression of the target gene. miRNA-29c inhibits tumor cells infinite proliferation and promotes apoptosis by regulating the signal pathways, oncogene, and cell cycle. miRNA-29c can inhibit the invasion and metastasis of tumor cells by regulating different target genes, signal pathways and mediating epithelial-mesenchymal transition. In tumor tissues, the lower expression of miRNA-29c, the higher clinical stage, and the poorer prognosis, so it can be used as an indicator of early diagnosis and prognosis. miRNA-29c is also closely related to head and neck cancer. Therefore, enhancement of the expression of miRNA-29c in tumor cells is expected to be a potential therapeutic strategy for cancer. Selective COX2 inhibitors and demethylated drugs can significantly increase the expression of miRNA-29c. miRNA-29c can be a new tumor biomarker and drug or gene therapeutic target.