By plane

The majority of visitors arrive in Mongolia through Chinggis Khaan International Airport (IATA: ULN), which is located 18 km to the southwest of Ulaanbaatar. Many locals still call the airport by its old name "Bouyant Uka". The airport was reconstructed in 1990, and the immigration, customs formalities and luggage delivery are relatively efficient.
MIAT [3] (Mongolian Airlines) offers direct international flights to the city from Berlin, Moscow, Irkutsk, Seoul, Beijing,Hong Kong and Tokyo. Domestic flights from ULN to Dalanzadgad, Moron, Khovd, Bulgan Khovd, Altai, and Arvaikheer are also available. Korean Air also flies daily from Seoul to ULN. Air China flies to and from Beijing. The Russian airline Aeroflot flies daily between Moscow and Ulaanbaatar.

By train

Direct (but long) journeys are possible from Mackow Rusia and Beijing, China on the Trans-Mongolian line of the Trans-Siberian Railway. Trains also run to the Chinese border towns of Erlian and Jining 3-4 times a week. There's also a daily train to/from Irkutsk in Russia, which can also be reached from Vladivostok at the eastern end of the Trans-Siberian.
Trains from Beijing run once a week (on Tuesdays) and seats can only be reserved at the International Hotel in Beijing (a ten minute walk north of the main Beijing rail station). The journey takes about 30 hours. Packing a face mask might be a good idea as sandstorms in the Gobi desert may cause difficulty in breathing.