Abstract: MicroRNAs is a class of endogenous non-encoding RNA. The researchers have found that miRNA has the role of oncogene or tumor suppressor gene， involved in the evolution of a variety of malignant tumors. Among all the miRNAs，we focus on miR-199a due to it’s important role in different carcinomas. Many experiment was done on miRNA-199a in cancers revealing it’s diverse expression and function in varies cancer types. In vitro studies suggesting that inhibition of miR-199a expression or prevent miR-199a with target gene interaction has a broad application prospect in the treatment of digestive system neoplasms. Since miR-199a play an important role on the cancer’s regulation mechanism， proliferation， apoptosis， invasion， drug resistance and metastasis. This review provide a comprehensive understanding of miR-199a and give a direction for it’s clinical value.