Abstract:G-CSF has been widely used in clinical, and it is not only used to treat neutropenia, but also used to reduce the mortality of cancer patients after chemotherapy. What’s more, G-CSF is the most widely used hematopoietic stem cell (HSC) mobilization agent at present. The review introduced the biology of G-CSF, and focused on the HSC mobilization mechanism of G-CSF. To explore the exact mechanism is necessary to improve the efficiency of G-CSF mobilization, and to provide a theoretical basis for the development of new hematopoietic stem cell mobilization agents in the future.