 This is a rater- blind, parallel assignment, randomized and active controlled study. The subjects investigated are outpatients or inpatient with schizophrenia from the Chinese Han race. The screening phase lasts for 1 week. The eligible patients enter the next randomized treatment phase. The titration duration is 1 week. After the first week, the patients are administered with a flexible dose regimen. In this study, the effective doses range of seroquel and risperidone are 600-750mgd and 3-6mgd respectively and the treatment duration lasts for 6 weeks. 