In recent years, an increasing number of studies have addressed the older adults' Information and Communication Technology acceptance, the majority of which concentrate on the use of computers and the internet. As smartphone use becomes further integrated into older adults’ daily lives, it is important to investigate how perceptions about and use of smartphones intersect. This study (1) proposes an extended Technology Acceptance Model and tests the relationships between Perceived Usefulness, Perceived Ease of Use, Attitude, Behavioural Intention, Self-efficacy, Technology Anxiety, and Social Support in older adults’ smartphone use by confirmatory factor analysis (CFA); and (2) analyses the specific differences between primary, medium, and advanced use level groups in each construct by Q-cluster and ANOVAs. We conduct a community-based survey with a sample of 1,006 older adults in East China. The data demonstrate that the extended model offered a good explanation of smartphone acceptance among the older adults, and the groups belong to different use levels show significant difference in all constructs. The findings indicate that digital divide is objectively inevitable in smartphone use, but the older adults are extremely diverse groups that do not uniformly conform to technology averse stereotypes.