The Arabic–Islamic cities is characterized with its narrow alleys and their hierarchy in width and containment. So the district of Jame Al-Kabeer which represents an example of the urban fabric of the old Arabic–Islamic city of Mosul has been selected to measure the degree of alley's containment enclosure by measuring the percentage of the width (W) of the alley to the height (H) and its integration within the Space Syntax theory. The shape of the integration core was peripherical integration core and the segregation core was in the center of the district. The percentage of the narrow alleys was 60.6% and the normal alleys 3.4% which represent the high degree of enclosure of the alleys in general. The statistical relation between the degree of integration and the degree of containment of the alleys was significant.
Key Words: Urban Design, Urban Space, Arabic – Islamic Cities.