Erbil as a historical city has faced a notable growth in different periods after the establishment of Iraq state in1920, especially after 2003 when it has witnessed its largest expansion rate. This, in turn has influenced the rate of the change of the urban form. This paper addresses the issue of the urban morphology of Erbil city in different periods since 1920. It presents the change of the urban form of the city through the frame of legislation which is supposed to reflect policies that meet a number of factors such as political, economic, social, cultural, environmental-climate, and technological. A descriptive and interpretative approach is adopted as an aim to provide an understanding of how and why this process of change has happened. The sources of data such as maps, photographs and legislative texts are used.