The study hypothesis is that the effect of extended release OROS paliperidone is not worse than that of Olanzapine in the treatment of schizophrenia as measured by the change in PANSS from baseline to the last post-randomization assessment. A flexible dose range is used in this study. The flexible dose of paliperidone is ranged from 3 to 12mg/day. The flexible dose of olanzapine is ranged from 5-15mg/day.The study medication is capsulized to maintain blind. Study medication must be taken orally once daily before 10 AM with or without food in a consistent manner throughout the study. Medication can not be chewed, divided, dissolved, or crushed. Treatment duration is 6 week each subject.
