Epilepsy is a relatively common disorder caused by varied reasons including brain defects, head trauma, infectious diseases, stroke, brain tumors, or genetic or developmental abnormalities. For the infant, the causes are premature birth, birth trauma, serious infections involving the brain, abnormal development of the brain structure, and genetic conditions. The structural changes of the brain showing as cortical dysplasia, necrosis or gliosis lead to dysregulation of cellular excitability and epilepsy. Although seizures are brief and infrequent, the caused temporally disability significantly impairs the quality of life. Infants who were diagnosed as epilepsy have the higher incidence of seizures in the first years of life than at any other time and epilepsy surgery is safe in very young children. Thus, there is a need for developing noninvasive methodologies based on EEG and/or MEG to localize the active tissue in a better means with more accurate information for helping surgery and to gain insights into how the disorder affects the development of normal brain functions.