▎ 摘　　要

NOVELTY - Preparing graphene and graphene quantum dot comprises (i) adding deionized water into a container equipped with a stirring device, adding soluble starch at room temperature or heating at 40-80 degrees C, stirring and dispersing for 10-30 minutes to dissolve (ii) adding solution obtained in step (i) into the hydrothermal kettle at a pressure of 8 Mpa, heating at 120-250 degrees C and carrying out hydrothermal reaction for 1-15 hours to obtain a brown material, and (iii) centrifuging the brown material obtained in step (ii) in a centrifuge at a speed of 3000-15000 revolutions per minute, separating a brown precipitate, lyophilizing to obtain graphene powder and then separating the upper layer of light yellow transparent liquid i.e. an aqueous solution of graphene quantum dots. USE - The method is useful for preparing graphene and graphene quantum dot. ADVANTAGE - The graphene and graphene quantum dot: has excellent fluorescent property.