By air:
The primary international airports in Beijing are:

• Beijing Capital International Airport (Code PEK), around 32 km northeast of Beijing's city center.
• Beijing Daxing International Airport (Code PKX), around 46 km south of Beijing's city center.

From the airports to Beijing, you can take a taxi (average cost from PEK, RMB 100 – 120). You can find other options here.

In the city:
More information about public transportation in Beijing can be found here.