A three-dimensional (3D) display including a memory unit, a signal processing unit, a display panel, a pair of shutter glasses and a timing controller is provided. In a first display period of a left eye frame period, the signal processing unit reading and outputting the first display data from the memory unit. In a third display period of a right eye frame period, the signal processing unit reading and outputting the third display data from the memory unit. In a second display period of the left eye frame period and a fourth display period of the right eye frame period, the signal processing unit outputting second display data. The timing controller controlling the shutter glass and driving the display panel according the first display data, the second display data and the third display data. As such, writing-in time and display time of frames can be increased.