A long-closed area at Beijing Capital International Airport will be used to handle domestic flights from Thursday to cope with increased passenger flow, the airport announced on Tuesday.
Section D of Terminal 3 was briefly used during the 2008 Beijing Olympics, and has since remained closed.
But the number of passengers using the airport has continued to rise, exceeding 80 million passenger trips last year.
Section D will handle some domestic flights operated by Air China. The airport authorities said passengers should take note of where to board flights as they must take an automated train to reach section D.
Section C of Terminal 3 will continue to serve domestic flights, while section E will still handle overseas flights only.
The airport has been the second busiest in the world in terms of passenger traffic for the past three years, following Hartsfield-Jackson International Airport in Atlanta, United States.