3.1　Introduction

After the development of the high-speed information technology, the human race dreams of a"door to door"high speed transport system just like the modern infor mation technology. The conventional automobile transport system has many dis advantages, such as traffic accidents, energy consumption, pollution, traffic jams, etc.Therefore, ground transportation with tracks is considered as one of the main stream transport methods of the 21st century.Traditional railway transport has not solved the future problems of ground transportation at high speed.High speed railway（HSR）emerges as the times require.Overall, airline, road traffic and HSR modes compete actively with each other in the distance range of 300 km to 1000km, and the result is that the HSR occupies obvious advantages in the market.The speed of 250-350 km/h with HSR cannot meet the demand for higher speed or ultra-high speed.In a 1000 km journey, people readily choose airline traffic.How ever, Maglev has a higher speed and better safety, so that the Maglev technology becomes one of the best choices for the future ultra-high speed transportation.The Maglev system can achieve speeds of 500 km/h or even thousands of km/h, have lower energy consumption and life cycle costs, attract more passengers, and pro duce less noise and vibration than high speed rail.In order to facilitate the reader’s understanding of Maglev transportation.This Chapter first introduces a general synopsis of the traditional railway, then discusses levitation phenomena, magnetic levitation concepts, permanent magnet（PM）levitation and the normal conductive Maglev.The superconducting Maglev, LTS and HTS Maglev, will be discussed in the next chapter.Various Maglev versions have different unique performances.In the constant pursuit of the"perfect"Maglev transportation, the new HTS Maglev train may be one of the best candidates.

More books and review articles about the Maglev vehicles can be found in the references（Maglev books and reviews at the end of this chapter）.