There are many factors affect positively and negatively the urban type and qualities. In the presents of complicated socio-economic and technological fast changes, monitoring such changes and predicting their impacts on the urban has become a difficult task.  
Geographic Information Systems provide many tools that can be utilized in documenting, monitoring and predicting the urban changes over period of time.
The research presents the application of a 4D GIS system that consider the time as a fourth dimension in studying and predicting the urban different changes. Moreover, A case study model for Mekkah city was developed to demonstrates the applications of these tools.
Traditionally, Mountains ring put limits to the urban area of Mekkah. During the eighties, a major urban extension happened because of a set of tunnel projects. These tunnels bridged the old city to the flat valleys behind the mountain ring.
Today, The old and historic area of Mekkah (known as the central area of Mekkah) is facing a major changes. Those changes covers almost all of its central area. A new projects, proposed by the private sector and supported by the authorities, aim to replace the exiting urban fabrics with new modern ones. This change is conducted through separate projects. Each one of these projects has its own time schedule, urban character and even building rules. Through the next twenty years, Mekkah central area will change completely.
The paper presents  a model to predict the urban changes over a certain period of time. Moreover, it presents a study of the different aspects’ of urban changes and their impacts on the urban qualities.
