A face recognition system, a method for establishing data of face recognition, and a face recognizing method thereof are disclosed. The face recognition system includes an image obtaining device, a facial analysis module, and a feature comparison module. The image obtaining device is used to obtain a registered facial image. The facial analysis module is used to analyze the registered facial image to obtain a registered facial feature, so as to determine a feature threshold of the registered facial feature. The feature comparison module is used to compare the registered facial feature with a facial feature of a plural facial images to register a facial feature of a similar facial image corresponding to more than a similarity threshold as a false-positive facial image feature. Such that the facial analysis module determines a false-positive threshold of the false-positive facial image feature.