▎ 摘　　要

NOVELTY - Preparation of upconverting nanoparticles and graphene quantum dot composite comprises taking upconverting nanoparticles of sodium yttrium fluoride doped ytterbium(III) and erbium(III), coating surface of the upconverting nanoparticles with a layer of silicon dioxide modified with an amino group, coating outer surface of graphene quantum dot with a layer of polyacrylic acid, and linking upconverting nanoparticles to form an amide bond with a carboxyl group on the surface of the graphene quantum dot. USE - Method for preparing upconverting nanoparticles and graphene quantum dot composite for simultaneous implementing near-infrared photodynamic therapy and fluorescence imaging (claimed). ADVANTAGE - The composite material has particle diameter of uniform size of about 35 nm, is capable of absorbing near infrared light, emits UV light and visible light, and transmits red light so as to realize the photodynamic therapeutic and fluorescent imaging at near infrared excitation.