Beijing Airport was opened on March 2, 1958. The airport then consisted of one small terminal building, which still stands to this day, apparently for the use of VIPs and charter flights. On January 1, 1980, a newer, larger Terminal 1 – green in color – opened, with docks for 10 to 12 aircraft. The terminal was larger than the one built in the 1950s, but by the mid-1990s, its size became relatively inadequate.

The first international flight to China and Beijing Capital International Airport was of Pakistan International Airlines from Islamabad.

In late 1999, to mark the 50th anniversary of the founding of the PRC, the airport experienced a new round of expansion as Terminal 2 opened on November 1 of that year. Terminal 1 was then temporarily closed for renovation after the opening of Terminal 2. September 20, 2004 saw the opening of a renovated Terminal 1, which at that time solely handled China Southern Airlines' domestic and international flights from Beijing. Other airlines' domestic and international flights still operated in Terminal 2.

Another round of expansion started in 2007. A third runway opened on October 29, 2007, to relieve congestion on the other two runways. Terminal 3 (T3) was completed in February 2008, in time for the Beijing Olympics. This colossal expansion also included a rail link to the city center. At its opening, the new Terminal 3 was the largest man made structure in the world in terms of area covered, and a major landmark representing Beijing as the growing and developing Chinese capital. The expansion was largely funded by a 30-billion-yen loan from Japan and a 500-million-euro (USD 625 million) loan from the European Investment Bank (EIB). The loan is the largest ever granted by the EIB in Asia; the agreement was signed during the eighth China-EU Summit held in September 2005.

Fresh from hosting the 2008 Olympic Games and adding its new terminal building, Beijing Capital has overtaken Tokyo Haneda to be the busiest airport in Asia based on scheduled seat capacity.

Due to limited capacity at Beijing Capital International Airport, a new airport in Daxing is being planned. The project was given final approval on January 13, 2013. Construction began in late 2014 and is expected to be completed in 2018. It is not yet clear how flights will be divided between the two airports; a possible plan is that all airlines of the Sky Team airline alliance are to move to the new airport.

Source: en.wikipedia.org