This study examines the aspect of variation of spatial qualities on the user’s experience in selected public rooftop gardens (RG) in Tokyo. Firstly, a combined method of fieldwork and simulation was used to describe the physical attributes in different environmental conditions to disclose the variation in RG settings. Secondly, these setting’s patterns are interpreted through parameters of experience to reveal the tendency of variation in each parameter. Finally, by connecting setting and experience, the quality factors of RG will emerge as a tangible and intangible relationship between Space Affordance with Usage and Image of Identity.