To study the procedure in cutting intracranial minimal lesions, intracranial minimal lesions were removed in 9 cases (male 6, female 3.) through keyhole in the guidance of frameless stereotaxy with robot. Robot image navigation orientation system was used to provide 3D images, and then these markers were made sure the coordinates of lesion target to guide the operating approach, locating anatomical structures,size of lesion and lesions to be removed in all the patients. Cases included 2 meningiomas, 2 brain abscess, 1 cyst of cysticercosis, 1 angiocavernoma, 1 metastasis tumors, 1 granuloma and 1 foreign body of metal from Mar 1, 2001 to June 1, 2001. The robot frameless stereotaxy provided accuracy of the intracranial lesions and anatomy. The postoperative neurofunction defects were not found. The outcome of operation was very good. The robot navigation system provided surgical navigational function: localization, orientation and guidance of the cutting intracranial minimal lesions in exact. It is useful in minimally invasive neurosurgery and is a good therapeutic method.