For improving elevator service in high-rise building, elevators are divided into group call banks; each bank serves a certain number of floors. The conventional procedure used in the traffic design of elevator systems could not applied for the elevator banking systems. A dynamic programming model of an entire elevator operation is developed in this study. Some evaluation performances of elevator system s design, such as average passenger waiting time, handling capacity and cost of floor space could be obtained from the model. These performances are used to determinate optimal number of banks, floors to be served by each bank, number of cars in each bank, speed and capacity of cars.