A system and method for image-guided microscopic illumination are provided. A processing module controls an imaging assembly such that a camera acquires an image or images of a sample in multiple fields of view, and the image or images are automatically transmitted to a processing module and processed by the first processing module automatically in real-time based on a predefined criterion so as to determine coordinate information of an interested region in each field of view. The processing module also controls an illuminating assembly to illuminate the interested region of the sample according to the received coordinate information regarding to the interested region, with the illumination patterns changing among the fields of view.