Brain tumors are not a rare disease, the diagnosis should be based on clinical examination, EEG recording and diagnostic imaging. The purpose of this study was to detenninethe relationship between brain functions and anatomical lesions in patients with brain tumors. The author conducted EEG recording and magnetic resonance imaging for 52 patients with brain tumors, those were diagnosed by pathology at the Central Military Hospital No.108, during the period from May 2009 to August 2011. The results showed that the typical features of brain tumors on EEG were slow activity (98.1 percent), focal attenuation of background activity (13.5 percent), asymmetric beta activity (23.1 percent), disturbance of the alpha rhythm (34.6 percent) and interictal epilepti form discharges (48.1 percent). 1.9 percent had normal EEG. EEG was non-specific with tumor location, size, number and types, but there are some certain relations. MR images in patients with brain tumor were very useful in the analysis of pathological EEG features, through which could understand the relationship between brain functions and anatomical lesions in patients with brain tumors.