The study included 26 patients with glioma involving motor cortical areas to assess the value of preoperative blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) in 3T high magnetic field for brain cortical mapping operation. With the guidance of preoperative mapping, all patients received microsurgery under awake anaesthesia to identify motor area by direct electrical stimulation. The tumor was resected at maximum with preservation of eloquent areas. Preoperative mapping was succeeded in twentythree patients; Primary motor cortex, premoter area, supplementary motor area and cerebellar motor related area were localized. There was good correlation between preoperative fMRI and intraoperative cortical stimulation results. BOLD-fMRI in 3T high magnetic field could non-invasively localize the brain motor cortex and show its relationship to lesion before operation, which may help neurosurgeons to optimize the surgical planning, guide the intraoperative motor areas mapping and resect the tumor with brain eloquent areas preservation. © Springer-Verlag Berlin Heidelberg 2006.