What is the route from beijing airport to Marriott City Wall? Thank you

If you are referring to subway route, no direct line can take you there. I suggest you take Airport Express Train to Dongzhimen first and then transfer to metro line 2 to get off at VJ Railway Station. Leave exit C and you can walk to your hotel in several minutes.

Apart from metro, you can take airport shuttle bus line 3 to the train station and then walk to the hotel directly!