Abstract: Osteosarcoma is a malignant tumor with a poor prognosis, and it has become the leading cause of cancer-related deaths in adolescents. However, due to its early high rate of lung metastasis and extensive resistance to chemotherapeutic drugs, clinical treatment of osteosarcoma remains a huge challenge. At present, advances in the early diagnosis and gene therapy of osteosarcoma have achieved some progress in fundamental researches and clinical applications worldwide. Among them, exosomes have great research prospects in the diagnosis and treatment of osteosarcoma.Exosomes are nanoscale microvesicles(40-100 nm) that can be secreted by a variety of living cells and have the ability to transmit multiple messages and functional substances such as mRNA, miRNA, DNA, and proteins.It can be produced and secreted by a variety of living cells and is present in a variety of body fluids and intercellular fluids. Because of its special existence and transfer form, as well as the information and substances it carries, osteosarcoma-derived exosomes can promote the tumorigenesis, invasion, metastasis, drug resistance, and immune escape of osteosarcoma in many ways. Using above characteristics, exosomes can be artificially loaded with targeted drugs or therapeutic genes, or they can be regulated in various ways to adjust the secretion and release in multiple tumor cells. In recent years,research on the role and application of exosomes in osteosarcoma has become a hotspot, but it still remains in basic research and has not yet been applied in clinical diagnosis and treatment. This article aims to summarize the functional mechanisms of exosomes on the invasion, metastasis and drug resistance in osteosarcoma, as well as the research progress in clinical diagnosis and treatment, hoping this will contribute to develop novel strategies to diagnose, treat and improve the prognosis in osteosarcoma.