Abstract: ［Purpose/Significance］Current research on older adults' public cultural services is still sparse, most of which focuses on older adults' information needs while neglect their needs of self-development and self-actualization. Focused on reading and incorporated the theoretical framework of "productive aging", this research explores the intrinsic driving force and heterogeneous motivation of older adults' participation in public cultural services by validating the reasons for participation scale for people aged 50 and above who have participated in public cultural activities.［Design/Methodology］With the reasons for participation scale, a questionnaire survey was conducted to investigate the reading behaviour and motivation of 394 people aged 50 and above in three universities of the third age. Exploratory factor analysis was conducted to explore their reading motivation. Moreover, logistic regression with robust standard error was conducted to examine the relationships between reading motivation and reading behaviour of the sample and to identify the heterogeneity of older adults' reading motivation.［Findings/Conclusion］There are four dimensions of reading motivation for people aged 50 and above, including achievement and self-actualization, challenge encountering, knowledge acquisition and social interactions. Meanwhile, reading behavior was positively associated with age (OR=1.1987, p=0.009). Besides, reading motivation of people aged 65 and above is heterogeneous. With strictly controlling the fixed effects of each category control variable, our analysis reveals that the reading behaviour of people aged 50 and above is mainly positively influenced by the motivation of "knowledge acquisition" (OR = 1.2681, p=0.046); Reading behaviours of people aged 65 and above were no longer associated with "knowledge acquisition", but negatively correlated with "facing challenges". Specifically, ceteris paribus, the probability of reading for people aged 65 and above reduces by 48.87% (p=0.045) as the score of "facing challenges" increases by one unit. It indicates that people aged 65 and above in China hope to cope with challenges of aging through reading, but they might encounter practical difficulties.［Originality/Value］From the perspective of productive aging, this research validated the reasons for participation scale for the older adults in China, and identified the multi-dimensional motivation of people aged 50 and above, which could provide a new perspective in studying public cultural services for the older adults as well as a reliable tool for future quantitative research. Meanwhile, the heterogeneous reading motivation of the older adults illustrates the necessity of paying attention to the special needs of them in public cultural services. This research also has practical implications for how to carry out reading promotion or other public cultural activities according to the older adults' special needs.

Key words: Old adults, Reading behaviour, Reading motivation, Reason for participation scale, Public cultural service for special groups, Productive aging