Commercial streets in heritage areas are very important elements that affect those area, as these streets contain important commercial activities with tangible heritage values represented by their distinct and diverse architectural and urban elements; and non-tangible heritage values represented by economic, social and cultural values. Therefore, these commercial streets containing those large group of values, must be preserved. The research problem arises from the fact there has been transformations occurring in the commercial activities occupying those commercial streets. Those transformation could be presented through the emergence of some new activities with that aren't matching to the heritage areas, the disappearance of other activities and the change in existing ones. This can affect the heritage values of those areas. Therefore, this paper aims to study the heritage areas, the types of their commercial streets, and the types of commercial activities occupying them, especially within Heliopolis area. After analyzing the case study, a group of transformations that occurred in commercial activities, could be observed. By studying the transformations, and their causes, the impact of transformation on the heritage areas could be deduced.