Patients with schizophrenia have many trouble in their life due to their thinking disorders such as delusion or hallucination. It is because they have a deficit in the ability which to systematize and integrate information. Therefore, they cannot integrate or systematize properly the integrated stimuli occurring frequently in a real situation. In this study, we suggest a virtual reality system for the assessment of their ability to integrate, memorize and react to integrated stimuli. The virtual reality system we developed provided multimodal stimuli, such as visual and auditory stimuli or visuo-spatial integration, and the patients was assessed and compared their thought flexibility and working memory abilities based on multi-modal manner by making the patient experience and react to multimodal stimuli. From this study, we could conclude that the VR could provide a patient with various stimuli in an immersive environment and allow the assessment of cognitive ability, and the identification of the relationships between cognitive functions.