The aim of the present study is to evaluate the efficacy and safety of quetiapine fumarate with daily dose 600-750mg/day in improving agitation and aggression for the treatment of Chinese acute schizophrenic patients hospitalised for acute phase over a treatment period of 2 weeks This is a 2-week, single-blinded, randomised, parallel-group haloperidol-controlled pilot study. After given of informed consent and undergoing screening procedures, the patients will be allocated to study treatment on Day 1. Patients should have a diagnosis of schizophrenia by CCMD-3 criteria with MOAS total score at least 10. Eligible patients will be randomised into quetiapine group or haloperidol group with 1-week dose titration (at least 600 mg/day for quetiapine and 8 mg/day for haloperidol after Day 7). After that, the patients should be treated by the defined dose range for another week.