As a class of excellent antibacterial materials, graphene and its derivatives have attracted much research attention. As an important member of the graphene family, however, graphene quantum dots (GQDs) is mainly focused on drug delivery, cancer treatment and biological testing. In this study, GQDs was prepared to kill Escherichia coli ($E.$ $coli$) under 655-nm laser irradiation. GQDs was synthesized from graphite powder. Under the laser irradiation, the as-synthesized GQDs rapidly converted the laser energy to heat and produced reactive oxygen species. Escherichia coli incubated with 0.6 mg/mL of GQDs was completely killed after 15 min of irradiation, while the Escherichia coli growth was not affected by GQDs or laser alone. With huge surface area used for loading considerable drugs, excellent biocompatibility, solubility and stability, GQDs may be a potential antibacterial material.