Abstract: Exosomes are cell-derived vesicles that contain protein and RNA from the same source and function. The vesicle has a diam-eter between 30and 100 nm. Exosomes are the natural carriers and have been recently used as drug delivery system for cancer treat -ment. MicroRNAs (miRNAs) function in RNA silencing and regulation of gene expression. They can exist as intracellular and extracellu-lar miRNAs. Extracellular miRNAs can function as secreted signaling molecules that affect receptor cell phenotype. They can also re -flect molecular changes in donor cells. Therefore, extracellular miRNAs can be potentially used for diagnosis and therapeutics. Studies show that the volume of exosomes in cancer patients' blood is higher than that in normal controls. The ability to package cancer-relat -ed miRNAs is a biological function of exosomes. In conclusion, specific miRNAs transferred by exosomes may play an important role in the pathogenesis of tumor or cancer. This paper presents a summary of research on exosomes as the carrier of miRNAs in the develop -ment and treatment of cancer.