Introduction: The central nervous system is one of the most sensitive microenvironments of the body that protected by the blood-brain barrier (BBB). BBB is a highly complex structure that tightly controls exchange of a range of small and large molecules, which protects the brain from damages and diseases. The promising feature of BBB in molecular movement from bloodstream into the nervous tissue affects delivery of several drugs to the brain. In order to increase drugs permeability through BBB various strategies have been developed. Among them, nanotechnology has provided effective methods for researchers in the field of drug delivery to the brain. Conclusion: In this paper, the structure and physiological properties of BBB as well as new strategies for drug delivery to the brain by using nanoparticles are discussed.