The characteristics of public spaces direct the behaviour of people within them, and consideration of the features of physical components of a space is essential for determining the degree of occupancy of that space. This study investigates the relationships between the characteristics of physical components of public open spaces and their density, and intensity of spatial use (DSU and ISU), applying to four selected public open spaces in Sana'a City in Yemen. Bedimo-Rung assessment tool-direct observation (Brat-do) is used in this study to examine the characteristics of the physical components of spaces, field surveys to determine their DSU and ISU values and behavioural maps to determine the diversity of activities in the spaces. The results showed a strong relationship between the DSU and the characteristics of the physical components of the studied spaces. The DSU was correlated with four of the five characteristics mentioned in the Brat-do tool: the features, conditions, aesthetics and safety of the spaces.