Abstract: Due to the unique quantum con?nement and edge effects, graphene quantum dots （GQDs） have exhibited extraordinary properties and potential applications. Herein, we summarize the advances on the preparation of GQDs in recent years, including the top to down routine from the graphite sheets through hydrothermal, electrochemical, and chemical oxidation methods, and the down to up routine from the carbon-contained organic molecules through solvochemical, sonochemical, and microwave methods. In addition, the applications of the GQDs in optical imaging, biosensor, and electrochemistry analytical fields are introduced. And based on the investigation status of the fluorescent mechanism of GQDs, it is pointed out that combining with the preparation of GQDs, the optical properties of GQDs should be especially studied in the future.