Chinese trains are divided according to their speed into various classes, identified with different letters and numbers. The letters refer to different classes:
G – High-Speed Electric Multiple Units (EMU) Train
This is the fastest running for long distance in China, the top speed of which could reach 350km/h. Currently, the G-train could finish the 1,068-kilometers Wuhan-Guangzhou High-Speed Railway in 3 hours, the 301-kilometers Shanghai-Nanjing High-Speed Railway in 73 minutes and the 458-kilometers Zhengzhou-Xian High-Speed Railway in 2 hours.
C – Intercity EMU
This is also the fastest kind, but runs for short travel distance between two nearby cities, such as the 120-kilomter’s Beijing-Tianjin Intercity Railway.
D – Electric Multiple Units (EMU)
This type is also called Hexiehao (和谐号, Harmony) or bullet trains in China. The designed top speed is 250km/h. They have been widely used for serving fast and frequent transport between main cities, such as Beijing-Shanghai, Shanghai-Suzhou and Shenzhen-Guangzhou.
Z – Direct Express
This type with a top speed of 160km/h is also an efficient transport for long-distance travel. Generally, they run directly to the destination or with some stops on the way. On the other hand, some are equipped with only soft-sleepers and soft-seats.
T – Express
This kind has limited stops on the routes, mainly in these major cities. The highest speed is 140km/h. Almost every T-series is equipped with soft-sleeper, soft-seat, hard-sleeper and hard-seat.
K – Fast
This series with a top speed of 120km/h has more stops than the T ones. They are equipped with air-condition and the four classes of berths.
The numbers are identified with four digits and usually start with 1, 2, 4 or 5. Its highest speed is 120km/h but runs slower than the K-series as a result of more stops on the way. Currently, most of this kind are equipped with air-condition.
With 100km/h’s highest speed, this should be the slowest type, having as many stops as possible. They are also numbered with four digits and start with 6, 7, 8 or 9. Most of them are green trains without air-condition.
These are specially taken by railway staffs, so they are not opened to public passengers.
L – Temporary
This series is in operation only during the peak travel time, such Chinese Spring Festival and the National Holiday. They will not be listed in the official fixed schedule. It is not advised to take this type if you have other options as they are routinely subject to delays.
Y – Tourist
This type is for the convenience of tourist and their destinations are the popular tourism cities. For example, there are Y-trains departing between Beijing and Qinhuangdao. Its speed is the same as the accommodation type.
S – Suburban
Running at 100km/h as the highest speed, this type is used for communicating city center and the suburban areas. It has no soft seats and sleeper berths as it only travels within short distance in day times. Currently, the S2 series travel between Beijing North Railway Station and the Yanqing County in the northern suburb of the city with stops at Qinghuayuan, Nankou, and Badaling Great Wall.