A method for manufacturing a light guide plate includes the following steps: (12) providing a photo mask having certain patterns of dots associated therewith; (16) using the photo mask to form an imprinting stamper; and (18) using the imprinting stamper to imprint an original light guide plate, thereby forming a light guide plate having the certain pattern of dots. The dots on the light guide plate manufactured by the present method are fine (i.e., with respect to microstructure), due to a high precision of the imprinting stamper. This precision can result in substantial or even entire uniformity of emitted light beams from the light guide plate. Thus, liquid crystal display devices adopting the light guide plate can provide satisfactory display quality. Therefore, the present method can be advantageously applied in manufacturing the light guide plate used in the liquid crystal display devices.