How to choose a seat when buying a train ticket?

For trains with C, D, and G prefixes, you can choose the position on the order when you buy tickets online, that is, the choice of facing the window, the aisle..., the row and the carriage cannot be selected, as shown in the figure. . <br/>Go to the ticket window to buy tickets, all trains can choose seats on the spot. . <br/>If it helps you, please click green to accept

C, D, G tickets have launched a seat selection function, and there is an additional option above the button to submit an order on the 12306 mobile client: seat selection service. <br/>Select "Seat Selection Service" on the 12306 mobile client terminal, and two rows of seats will appear at the bottom of the page. Take the purchase of two tickets as an example. The window is the farthest. There are three seats in a row and two seats in a row on the train. You can also choose from this seat map to meet the needs of sitting next to or not sitting with strangers. After the 12306 mobile client terminal is selected, the system will automatically allocate cars and seats. The ticket will be issued after the confirmation is correct and the payment is completed.