Abstract: Diarylethene derivatives containing naphthalene imide was designed and synthesized. The diarylethene derivatives was successfully grafted onto the amino group of the watersoluble upconversion Er/Ho nanoparticles in the form of chemical bonding. The emission spectrum experiment of nanoparticles in solution states proved that the nanoparticles prepared by this method has a good dual mode luminescence properties and  the function of optical switch. After irradiation under the light of 365 nm, the fluorescence was quenched. The nanoparticles were lighted up again through the irradiation of 980 nm laser. The resultes obtained could provide the theoretical foundation for nanoparticles in tracking and monitoring in biological imaging.