Recent advances in nanotechnology have provided a variety of nanostructured materials with highly controlled and interesting properties. Nanomedicine is one medical applications of nanotechnology, which has improved cancer treatment in past few years. Liposome and polymer based nanomaterials have been clinically approved as therapeutic agents for cancer therapy. These nano-platforms exhibit various advantages, including high surface-to-volume ratios, controllable drug release profiles and specific targeting capabilities, which make them promising drug delivery carriers. However, the broad applications of these traditional nano-materials are still hindered by their low therapeutic and delivery efficiency, rapid drug clearance and biodegradation. For example, current nano-carriers face great challenges of delivering cerebral therapeutic drugs across blood brain barrier (BBB) to heal neurological disease. In addition, nano-carriers loaded with genetic therapy agents usually show limited capability of escaping intercellular subcellular compartments, reducing their delivery efficiency. Thus, the development of comprehensive, reliable and multifunctional nano-platform for diagnosis, intracellular imaging and therapy is crucial for nanomedicine applications. Nano-size platforms possessing tunable physicochemical properties and multi-therapy modality are considered as effective tools for diagnosis and therapy. They can provide real-time diagnoses, high resolution imaging and efficient therapy. In this dissertation, I synthesized three types of multifunctional nanomaterials: fluorescence silica nanoparticles, fluorinated nanomaterials and mesoporous Au Pt nanoparticles. I developed fluorescence silica nanoparticles to achieve receptor-mediated delivery across the BBB. The research suggested that the transfer efficiency was improved by reducing the particle size. The developed fluorinated nanomaterials could successfully and rapidly escaped from early endosomes. This superior escape ability of the fluorinated nanomaterials from endosomes will make them an effective tool for the cellular delivery of biological molecules. The specific targeting mesoporous Au Pt nanoparticles were synthesized as nanosensitizers. Experiments showed that they could be used for PDT/PTT for cancer cells in vitro. The nanosystems developed in this work have great potential to be applied for multimodal tumor therapy.