Statement of the problem. In this study, airports terminal buildings, the capacity of the airport terminal buildings, and the factors affected the capacity were searched. It was determined that the airport terminal building may vary and their spatial functions affect all airport functions. It was observed that any positive/negative change in the functions of terminal buildings affected the operation of terminal building. Method: A program was developed as a result of observations and studies while investigating the airport terminal buildings. Applicable regulations and the factors which negatively affect the capacity of the terminal, with improvements on the total capacity of the system were investigated.