The research of comfort in urban public spaces has become increasingly important for improving environmental quality and encouraging people spend more time in outdoor activities. Among numerous approaches to understand comfort perception, the rational indices based on heat balance theory have prevailed to guide the research and practice in urban planning, design, and management. The limitations of a solely rational index-based approach reveal the necessity for a more comprehensive understanding of comfort by considering a wider range of influential factors from both individual and environmental perspectives during the assessing process. This study conceptualizes individuals’ comfort in urban public spaces as a latent construct, which is measured by indicators regarding perceptions on multifarious meteorological variables. The conceptual framework has been introduced involving hypothetical relationships among individuals’ comfort, attitudes, and environmental perceptions in urban public spaces. A series of field work including microclimate measurements and questionnaire-based surveys were carried out in two public squares in Changsha, China. Based on the dataset derived from 372 questionnaires and related meteorological measurements, this paper examines the relationships between the physical microclimatic variables, individuals’ socio-demographical characteristics and environmental attitudes and perceptions, and outdoor comfort assessment. The estimation results of the structural equation model quantitatively verified the conceptual framework at large, as many hypothetical relationships are identified, which indicates the importance of individuals’ role and the psychological factors in modeling comfort perception. This approach improves the understanding of comfort assessment, contributes to improving the quality of urban environment and the practices of urban planning and management.@en