A trajectory prediction system for predicting a point of impact of an object shot from a ballistic device is provided. The trajectory prediction system includes an objective lens, an eyepiece lens optically coupled with the objective lens, an image sensor, a processor, and a display electrically connected to the processor and the image sensor. The image sensor, the processor, and the display are disposed between the objective lens and the eyepiece lens. When an external light reaches the image sensor through the objective lens, the image sensor transmits a first signal to the display, and the display shows an image according to the first signal. The processor calculates the trajectory of the object and transmits a second signal to the display, and the display simultaneously shows the image and at least one predictive point of impact according to the first and second signals.