What do the letters on Chinese train numbers mean?
Every train in China carries a letter and a number, and that letter tells you almost everything before you look at the timetable: how fast it is, whether it has sleepers, and roughly what it costs. Here is the whole alphabet, decoded.
The nine letters
Ordered roughly from fastest to slowest. If the departure board shows a letter you have never seen, it is almost always one of these nine.
The flagship fleet. G trains are the fastest, the most frequent and the most expensive. Every G service is an electric multiple unit with reserved seats only — no standing carriages are sold once seats run out.
Short, dense hops between neighbouring cities — Beijing–Tianjin, Shanghai–Suzhou, Guangzhou–Shenzhen. Turn-up-and-go frequency, often every 10–15 minutes.
Same family as G but a step slower and noticeably cheaper. On long routes D trains often run overnight with sleeper compartments, which makes them the best value for a night of travel.
Conventional (non-high-speed) overnight trains that skip most intermediate stops. Typically all-sleeper, departing late evening and arriving early morning — a rolling hotel on the classic Beijing–Shanghai line.
Faster conventional trains with more stops than Z services. You will find a mix of hard seats and sleepers; useful where no high-speed line exists.
The workhorse of the conventional network and the most common letter on older lines. Slow, stopping, cheap — and the only option to some smaller towns.
Seasonal tourist services, often steam-hauled or scenic slow lines. Timetables are published per season and seats are usually sold as packages.
Extra trains added for peak periods — Spring Festival, Golden Week, summer holidays. They appear in the timetable only days ahead and are the first to be added to our search results.
City-region commuter rail, such as the S2 line from Beijing to the Great Wall at Badaling. Cheap, frequent, and bought like a metro ticket rather than a long-distance reservation.
Why the letter matters more than the number
The same city pair can be 4.5 hours on a G and 12 hours on a K — at roughly a third of the price. Comparing departure times without comparing the letter is how people end up on the slow train by mistake.
Reading the number
The digits are not random, and they explain the small differences you see between two trains on the same route.
| Number | What it tells you |
|---|---|
| G1, G7, G21 | Two-digit numbers are flagship services — few or no intermediate stops, fastest timings, first to sell out. |
| G6022, D311 | Four-digit numbers generally make more stops, so they take longer on the same city pair. |
| Even vs odd | Trains heading towards Beijing carry even numbers, trains heading away carry odd ones. Useful when you are not sure which direction you are facing. |
| Two letters, one train | On some conventional lines the same physical train changes letter mid-route (for example a Z segment that becomes a K). The letter that matters is the one printed on your ticket. |
Which train should I book?
| Your situation | Book this |
|---|---|
| Day trip, 1,000 km or less | A G train. Fastest door-to-door, and the timetable is dense enough to pick a convenient hour. |
| Overnight, want a bed | A D sleeper or a Z direct express — you board in the evening and wake up in the next city. See seats and sleepers for which berth to pick. |
| Neighbouring city, under an hour | A C intercity. Turn up, buy, board — no need to plan weeks ahead. |
| Tight budget, flexible time | A K or T. Roughly a third of the high-speed fare, at roughly three times the journey. |
Every train in our search results is labelled with its letter, so you can see exactly what you are booking before you pay.
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