The granulocyte colony-stimulating factor (G-CSF), now referred to as CSF3, is a very important cell growth factor that supports the proliferation, survival, and differentiation of neutrophilic progenitor cells, and also is a strong immune regulator of T cells and a promising therapeutic tool in acute graft versus host disease (GVHD). G-CSF acts by binding to its receptor G-CSFR (also called CSF3R), a member of the cytokine receptor type I superfamily, which after binding with G-CSF activates the canonical Janus kinase (Jak)/signal transducer, activator of transcription (STAT)and Ras/Raf/MAP kinase pathways. G-CSF has been applied to the clinic to treat congenital and acquired neutropenia before or during courses of intensive chemotherapy. It has also been applied to mobilize hematopoietic stem cells into the peripheral blood for Auto-or allogeneic transplantation, and the priming strategies designed to enhance the sensitivity of leukemia stem cells to cytotoxic agents in protocols aimed to induce their differentiation, accompanying growth arrest, and cell death. With the rapid development of molecular genetics and clinical research, CSF3R mutations have been implicated in the progression of severe congenital neutropenia (SCN) to leukemia. Recently, CSF3R mutations have been discovered frequently in chronic neutrophilic leukemia (CNL). Such findings might provide the theoretical basis for the targeted therapy. In this review, the clinical application of G-CSF receptor in hematonosis is briefhy summarized.