Plaza spaces in Old Sana'a City are distinguished by their formations deeply rooted in history, with magnificent artistic, architectural, and historic values that reflect man's creativity and distinction in that place. They are also a major component of the material heritage environment that embraced the immaterial heritage embedded in the different human aspects of the city's residents. Over centuries, various human activities followed (social, economic, cultural, and political), causing plazas to have all inherited values of the cultural heritage as well as the product of man's relationship with the surroundings. The problem discussed here is that plaza spaces in Old Sana'a lack vitality within the urban texture of the city. This is because the original human role, previously tangible, disappeared. These spaces were not only formed by material elements (buildings), but the local community had a crucial role in forming them through circulation. These spaces were vivid all the time because of the social, cultural, and economic activities that were held in their purview. Now, most plazas are deserted, their functions altered, and are not significant to people as was the case in the past. The research aiming at reviving plazas as an important space in the forming the urban texture of Old Sana'a City. To achieve the aim of the research, the inferring analytical methodology was adopted. The first part of the research is concerned with studying plaza spaces in Old Sana'a City, their types, and function in the heritage environment of the city. The second part of the study addresses an analysis of the human aspects of the society and their role in setting the plaza space. The third part reviews the major changes that influenced the human aspects, and the major factors that contributed to the vanishing of the human role in plaza spaces – leading to neglect, deterioration, and consequently lack of interest in the heritage environment surrounding these spaces. The fourth part will set proposals for reviving the human role in plaza spaces of the Old Sana'a City, in order to revitalize these spaces within the Old City. The final part displays results and recommendation drawn from the study. The research concludes that factors contributing to making changes in the human aspects related to plaza spaces in Old Sana'a include: immigration, cultural and economic opening, and the technological progress after the 1962 revolution, as well as the take over by the republican regimen. There is a need for enhancing and supporting human activities related to the traditional social and cultural values of the society, in addition to creating new activities that achieve sustainability for these spaces to act efficiently within the texture of the city.