1 time. According to the Civil Aviation Law of People's Republic of China (PRC), the Civil Aviation Development Fund is a fee set up to support the development of civil aviation. Passengers need to pay the Civil Aviation Development Fund when purchasing domestic or international flight tickets. When the ticket is changed, passengers only need to pay the Civil Aviation Development Fund once. Even if the same ticket is changed several times, as long as the last flight of the passenger is the same ticket, the date and flight information will not change, and the Civil Aviation Development Fund will only charge it once.