Bring your passport
New regulations are in force as of 2011. Foreigners must show their passport to purchase train tickets. Chinese citizens show their ID cards.
China is building a high-speed passenger rail network, similar to French TGV or Japanese Shinkansen “bullet trains” but far larger. The overall plan calls for 13,000 km of lines in a national high-speed passenger network by 2012, and 20-odd thousand by 2020. Over 8,000 km (5,000 miles) were already in service as of 2010.
These are easily the best way of getting around China where available. The trains are clean, comfortable and modern. Seating is comparable to that in an airplane. Most tickets are for assigned seats; no-seat tickets are sometimes sold in limited numbers, but unlike regular Chinese trains, there is never a mad crush with more people sitting in the aisles than in seats. Also unlike other trains, no smoking is allowed, including toilet and between carriages. Prices are reasonable and, on most routes, departures are frequent.
The fast trains are called CRH, China Railway High-speed. At some train stations there is a separate CRH ticket office or even vending machines; at others, CRH tickets are sold at separate counters in the main ticket office. In either case, just look for the “CRH” signs or logo. Note that non-Chinese can no longer use the vending machines; you must go to a counter so they can check your passport.
The speeds attained vary considerably from line to line. The technology used also varies. Nearly all the rolling stock is now manufactured in China, with much of the technology comes from abroad. The Canadian company Bombardier, Japanese Kawasaki, German Siemens and European Alstom have been involved.
The letter prefixes on train numbers indicate the type of train. From fastest to slowest, the fast trains are:
G: latest generation CRH, all with top speeds of 300+ km/h (G is for 高鉄）
C: intercity high-speed rail. Top speed 300 km/h. Only found on the Beijing–Tianjin–Tanggu line.
D: earlier generation CRH, with top speeds of 250 km/h (155 mph) （动车）
The slower trains (not high-speed train) are:
Z or T: intermediate-speed non-CRH trains. Some of these get up to 160 km/h (100 mph) ，Z means 直通 direct with very few stops at start of journey. T is 特炔 special fast.
K or no letter: slower, cheaper and more crowded trains. K is 快 meaning fast and is the most common train, definetely faster than no letter train which would stops at every station.
On most trains, there are just two classes of seats, first class and second class. Both classes are comfortable, though first has noticeably wider seats. Some trains also have a limited number of VIP sightseeing class or private seat cabins. Some long-distance runs have sleeper cabins.
Taking the fastest train Is not always the best way to travel between cities, for example, between Beijing and Xi'an, it might be better to take the overnight T or Z train instead of travelling 6-7 hours on the D train. You save one night hotel bill and one day travelling time.
The price difference for the classes is not enormous. For the Fuzhou-Shanghai D train (six hours and well over 1000 km), for example, second class is 282 and first 330-odd. There is a K train for only 130, but it takes 17 hours on a less direct route and is very crowded. Unless your budget is extremely tight or you cannot cope with six hours in a non-smoking train, the fast train is hugely preferable, easily worth the cost difference.
Some trains have a dining car and nearly all have attendants selling drinks and snacks from carts which they roll up the aisles. Many stations have vendors on the platforms as well. All these tend to be expensive, though, so it is worthwhile bringing your own food and drink.
As of late 2010, the following lines are in service:
Beijing - Tianjin – Tanggu, China's first 300+ km/h class line, opened in 2008 just before the Beijing Olympics
Beijing South to Tianjin, 117 km in 30 minutes (non-stop) or 35 minutes (stop in Wuqing), 1st class ¥66 and 2nd class ¥55
Beijing South to Tanggu in seaside (where you can board a ferry at the Xingang Port to Japan, Korea and other destinations), 51–52 minutes (non-stop) or 54–56 minutes (stop in Tianjin), 1st class ¥84 and 2nd class ¥70
Beijing–Tianjin–Jinan–Xuzhou–Nanjing–Shanghai, 300 km/h line opened June 2011
Wuhan - Changsha - Guangzhou, once China's flagship high-speed rail line, world’s fastest commercial train service in term of average speed
350 km/h G-series train line opened in December 2009, 968 km in slightly over 3 hours, 1st class ¥780 and 2nd class ¥490. The line, like all other lines in China, has been slowed down to 300 km/h, but there're discussions to restore the 350 km/h speed in the next few months.
The D train from the main Shanghai station to Nanjing was one of the first CRH lines and is still in service. It takes a bit over two hours.
A new G train line opened in July 2010, running from the new Hongqiao Station in Shanghai, right next to the airport and on subway Line 2. Shanghai-Nanjing time is now 73 minutes for non-stop service; some trains also make intermediate stops.
An even newer line is under construction and will cut the travel time to just under one hour, due in late 2011.
As the CRH network comes online, many existing lines are becoming freight-only lines so China's overall freight capacity is being improved as well.
Partly because of competition from the fast trains, some of the Chinese domestic airlines are reducing prices, so there are now quite a few bargain flights. See discount airlines in Asia for some possibilities.
China is trying to sell this technology to other nations; they are negotiating with several countries in Latin America to build a network there. They are also negotiating to extend their network across Asia, with high-speed links all the way to Moscow, Singapore, and New Delhi via Burma. This is a slow process; as of mid-2011, only the link to Vientiane is confirmed. See this news coverage.