FA-PEI-NaGdF4:Eu nanoparticle was synthesized by a facile strategy. FA-PEI-NaGdF4:Eu nanoparticle as a novel fluorescence/MRI dual-modal nanoprobe can be used for targeted cancer cell imaging. Novel fluorescence/MRI dual-modal nanoprobe has good biocompatibility and great potential for biomedical application.