Quetiapine fumarate (Seroquel) is a dibenzothiazepine derivative, which is widely used in the world. It has the indications in schizophrenia, bipolar mania and depression approved by FDA. Quetiapine fumarate has been used in China for almost 10 years, which is in the treatment of schizophrenia. The indication of bipolar mania has been approved by SFDA recently. Exploration of the relationship between the dose and efficacy has been a hot spot in the clinical practice as the drug has a broad action spectrum and wide dose range (200mg/d－800mg/d).