The invention discloses a method for displaying a stereoscopic image, wherein the stereoscopic image includes a first-eye image and a second-eye image. The method is to firstly calculate a shift of the first-eye image with respect to the second-eye image. Then, the method moves the first-eye image for a length of a shift. Afterward, the method outputs the moved first-eye image and the second-eye image to display the stereoscopic image. Thereby, the parallax of the stereoscopic image is adjusted, so as to enhance the synthesizing effect of the stereoscopic image created.