Kleene-Levin syndrome (KLS) is a rare disorder primarily occur in adolescents,is characterized by intermittent episodes of hypersomnolence,cognitive and behavioral disturbances and hyperphagia.Our case describes a 14-year-old Chinese girl with recurrent hypersomnia.She experienced four attacks before diagnosed,behaved normally between each attack,and present down mood before each attack.She monitored in our sleep center using polysomnography during an episode.The result was negative for sleep apnea and the electroencephalogram signals showed no epileptiform activity.The patient was treated with methylphenidate 10 mg daily for 1 month and was under weight controll and behavioral Intervention treatment after withdrawn from medicines.She didnt experienced attack again.