This pilot study examined the age-related decline of classifier usage in Southwestern Mandarin through comparing classifier score and the number of the default classifier ge among older adults aged 50-87 years. They were grouped into healthy, mild cognitive impairment (MCI) and Alzheimer's disease (AD) groups based on Montreal Cognitive Assessment. AD group used significantly more inappropriate classifiers and the default classifier ge than healthy group. Results also showed a significant correlation between cognitive/semantic abilities and classifier usage, indicating that the deficit of classifier usage was associated with declined cognitive/semantic abilities. Decline of semantic cognition with aging, specifically semantic store and processing, has been postulated as possible underlying explanation. However, no significant difference was found in classifier usage between healthy and MCI groups, which might reveal that their classifier usage and semantic cognition was still normal.