By 2021, the urbanization rate of China had reached as high as 64.72%. At the same time, the efficiency-driven urban planning paradigm had shifted to that of an efficiency-and-fairness intent. Fairness refers to the publicness of public open spaces (POS) as an indicator of an inclusive and fair city. The authors are interested in the measure of POS. However, few studies evaluated POS by effective assessment frameworks and tools. Based on this critique, the authors propose to integrate a qualitative assessment tool—the Star Model, with that of a quantitative assessment tool—the Space Syntax, for assessing publicness and enhancing the understanding of POS (streets and squares). There are two conclusions: (1) The combined use of the quantitative and qualitative tools provides accuracy and enables a comprehensive understanding of public spaces, namely, the mechanism of publicness—of both bottom-up POS and top-down POS. On the one hand, bottom-up POS is an outcome of the spatial system enabled by a networked structure of space. On the other, the publicness of top-down POS can be largely twisted by the government and urban designers rather than the residents. (2) This research has introduced an improved combined tool for the benefits of both policymakers and planners.