Cancer is one of the leading causes of death, accounting for 8.2 million deaths worldwide in 2012. A major reason for this high mortality rate lies in our inability to deliver therapeutic agents only to the tumor sites without inducing severe adverse effects on healthy tissues and organs.In medicine, nanotechnology has sparked a rapidly growing interest as it promises to solve a number of issues associated with conventional therapeutic agents, including their poor water solubility (at least, for most anticancer drugs), lack of targeting capability, nonspecific distribution, systemic toxicity, and low therapeutic index.They display unique physical and chemical properties due to their size, which is in the same range as antibodies, receptors, nucleic acids, proteins and other biological macromolecules. Nanoparticles form the basis for a huge variety of pharmaceutical and medical applications, including diagnostics and drug delivery, and have special potential in cancer therapy. The enhanced permeability and retention (EPR) effect is a unique feature of most tumors, allowing nanoparticles of appropriate sizes to accumulate more in cancerous tissues than in normal tissues.Nano targeted drug delivery system is a drug delivery method that can help the drugs go to targeted site by using components, vehicle, drug bullet, in nanoscale. Ligand help to link the vehicle which contains drug with the cell so the drug can release in the right place. Vehicle carry and protect the drug and drug bullet, loaded in the vehicle, have chemical properties to cure disease.The nanoparticles used for drug delivery can be readily fabricated from either soft (organic and polymeric) or hard (inorganic) materials, with their sizes being controlled typically in the range of 1–100 nm and compositions/ structures being engineered to load anticancer drugs in a variety of configurations.Hence, it is anticipated that precisely engineered nanoparticles will emerge as the next-generation platform for cancer therapy and many other biomedical applications.