Integration of various cerebral cortical functions results in performance of mentality. Given to mental status examination evaluates the general performances of cerebral cognitive function, it becomes indispensable to a comprehensive neurological examination accordingly. Whereas mental status examination evaluates complex cerebral function, it should be interpreted and administrated more cautiously than other ordinary exams in clinical application. In this report, we introduce essential concepts of mental status examination, some important skills in testing, and a few useful tests used in a medical center.