The reliability and validity of the Chinese vesion of the Cohen-Mansfield Agitation Inventory (CCMAI) were studied in 164 demented patients. The agitation pattern in Chinese elderly was also examined in this study. The CCMAI demonstrated high validity, test-retest reliability, and interrater reliability. Eighty-five precent of demented patients manifested one or more agitated behaviors at least once a week. Factor analysis yielded three subtypes of agitation: physically aggressive behaviors, physically nonaggressive behaviors, and verbally agitated behaviors. There was a linear upward trend in physical aggression as one progressed from one Global Deterioration Scale stage to the next. Community-living patients showed higher physically nonaggressive and verbally agitated behaviors, whereas institution residents exhibited a significantly higher level of physical aggression. The differences between residential and institutionalized patients need further research. Future study should focus not only on the behavioral disturbances; medical, psychological, and environmental factors should be taken into account to provide a more accurate profile.