Abstract: Larotrectinib (also called LOXO-101, ARRY-470, and VITRAKVI^®) is a kind of new high selective and broad-spectrum small molecule that is administered orally. Larotrectinib is tropomyosin receptor kinase (TRK) inhibitor and is used in the treatment of neurotrophin tyrosine kinase receptor (NTRK) gene fusion in children and in adults. Based on use of larotrectinib against solid tumor in a variety of NTRK gene fusion, larotrectinib has a good curative effect and security. On November 27, 2018, the drug was approved by the Food and Drug Administration (FDA) for the first time in the world. It is used in the treatment of no unknown drug resistant mutations, a broader shift, or partial surgical treatment, and after the treatment of disease progress of NTRK gene fusion in children and adult patients with solid tumor. This article reviews the latest research progress in the research background, structure, and mechanism of action, clinical trials, adverse reactions and treatment, and drug resistance mechanism of larotrectinib.