**Abstract**

Modern permanent magnets are the essential materials for many industries and technologies. All strong permanent magnets that contain rare earth element have wide range of application. Different processing technique, material and manufacturing methods are used to produce different types of rare earth magnets. New developments and improvement in properties are proposed based on the addition of nanocrystalline materials to address the effectiveness of rare earth magnets which is beneficial for different application. This chapter reviews the fundamental aspect and progress of rare earth modern magnet along with the need of essential key factor for future development of cost-effective rear earth permanent magnets.

**Keywords:** magnets, rare earth, nanocrystalline, NdFeB, Sm-Co, SmFeN, sintering
