Abstract: Nanomedicine has been developed and applied for a long time. Although the rapid development of engineered nanoparticles with integration of different functions shows a great promise for the diagnosis and treatment of disease, nanoparticles responsible for in vivo targeted imaging of tiny tumors have not been available in clinic. Low sensitivity is one of the major problems. In this case, "Systems nanomedicine" has recently become an area of increased research focus. A pair of nanoparticles with signal amplification can be designed for this purpose. First, targeting nanoparticles are designed bearing a great number of signaling molecules, while accumulating nanoparticles with fluorescence activity can specially bind to the signaling molecules on the surface of the targeting nanoparticles. With this pair of nanoparticles, signals for the imaging can be amplified because of large quantities of accumulating nanoparticles on the tiny tumors. Based on this principle, we constructed a pair of ferritins based targeting/accumulating nanoparticles to optimize the crucial technological issues including targeting ability, loading capacity and specific interaction between them. The results showed that RGD/HSA-FTH1-biotin targeting nanoparticles could not only target and bind to integrin α_vβ₃, but also carry large amount of biotin moleculars (with a molar ratio 40). At the same time, mSA-FTH1/FTH1 accumulating nanoparticles was found to be able to specifically bind to biotin. These results suggested a successful fabrication of the systems nanoparticles, which therefore laid a solid foundation for the diagnosis and treatment of tiny tumors in vivo.