ABSTRACT
Public open spaces are important assets that play a significant role in city lives, based on which a great number of behaviour-based studies are being conducted. These studies often use one or more case studies to observe people's preferences and usage habits and to investigate their influencing factors such as outdoor thermal comfort, environmental conditions, urban configuration, and local settings. Because the subject is complex and falls within the purview of multiple academic disciplines, it is a challenging task to understand the current status and development trends of existing studies. To fill this gap, this article presents a systematic review of quantitative evidence-based behaviour studies in public open spaces. Following the PRISMA method and searching using eight academic search engines, full texts of 116 research articles have been included for this review. The main contributions of this review are that: (1) it proposed a relatively complete system that categorizes people's behaviour in public open spaces;(2) it introduced outdoor subjective influencing procedure including behaviour, feeling and health impacts;(3) the review illustrated the distribution of existing research as well as research trends;and finally (4) the article also timely discussed the influence of the COVID-19 on people's behaviour in public open spaces. The authors consider this article to be useful as it can facilitate further behaviour-based studies in public open spaces. With a robust classification and future trend discussion of factors associated, fellow researchers, urban designers, city managers, and policymakers are easier to integrate and use the knowledge learned.