this study is a randomised double blind,patients and researcher, crossover clinical trial.the objective of study is assessment of Efficacy of combined extract of Nigella Sativa and Thymus Vulgaris on refractory seizures in childrenin Ahvaz city.The patients will be divided randomly into two groups.15 Patients in the intervention group receive NS and TV extract as an adjunctive therapy. 15 patients in the control group receive placebo with same shape.Then all the patients will be evaluated for two weeks (as washout period) after two months in the terms of duration and the frequency of epilepsy and side effects. Then after crossover the prepared extracts and placebo will be administrated for groups for another two months . Then the frequency and duration of seizure will be compared between groups.