old historical cities are distinguished by beautiful architectural environment , fantastic natural landscapes and human architectural heritage which was existed due to long historical accumulations and this heritage is mixed with natural environment and they both constitute unique joint entity which resulted from cultural and social and economic civilizations for that cities. Historical cities are violated in terms of beautiful features changes by horizontal and vertical additions for that arenas, spaces , markets and buildings and thamar city is like the other Yemen cultural and historical cities. Through this research , we focus on highlighting the importance of historical cities and Thamar is example for the purpose of re-planning of main areas which will be the cornerstone for development and economic investment and attractive areas that activate the other parts of the city. This research deals with three main topics , the first one is to present the problem and the second one is to re-plan the axis that links between the Great Mosque and Sun School , which passes through the center of the city and to remove additions and deformations and the last one is to propose establishing investment center, which is supposed to be like basis for preserving and developing the historical city . The research reached to proposal that is aimed to open axis that links between great mosque and Sun School and to establish tourist and economic investment center to activate and rejuvenate historical cities.