What bus can i take from Tiananmen sq / close area,to Capital Airport?

1. Take metro line 1 from Tian'anmen West Station to Xidan Station, Exit C. Then, take shuttle bus line 2 from Xidan Civil Aviation Building to PEK for CNY 24.
2. Yes, you can take bus line Te 13 from West Railway Station. Then, change to bus line 877 to Badaling.
3. Take bus line 877 back to Deshengmen Station. Then, take bus line 5 from Deshengmen to West Gate of Zhongshan Park Station, and you can see Tiananmen Square. :)