Bam Citadel is a unique complex with some mediocre buildings in it. Construction started in the Achaemenid period (550–330 BC) and is still being completed and repaired up to the 21st century. Although the Bam region is located in south-western Iran in an active seismic zone, the City of Bam had not reported any major historical earthquake before 26th Dec. 2003. The massive earthquake that day killed or injured more than 37,000 people and most of the city collapsed. Bam Citadel became a unique adobe complex for the World Heritage community after this disaster. According to the surveys, the earthquake caused damage to about 23% of the ancient monuments close to and inside the Citadel. Most of the ruins were the parts that already added to the main body of work or were repaired during the last intervention of 1993. For this reason the technical method, used for the enhancing of the adobe building, is highlighted as the main task. There are four items which are very important for any seismic upgrading in heritage sites: seismology of the area, quality of the construction, function of the building and cultural values. A wide variety of intervention strategies and techniques have been considered for the repair and the seismic retrofitting of the adobe buildings in the Citadel. With respect to that point, the possible relationship between the cultural values and seismic upgrading are always polar opposites. Obviously the buildings in Bam Citadel have many problems, for example the geometry data are not available, there are large variability layers, construction sequence is unknown, existing damage in the structures is very serious, regulation and codes are non-applicable and so on. In fact in this research I am trying to adjust the stability and safety measures with values of the cultural heritage property as much as possible; on the other hand I am trying to optimize the strengthening methods to an acceptable amount of side affect on values. This PhD thesis focuses on the strategies and the techniques that have been applied to preserve the historical monuments and to evaluate the traditional and modern engineering methods that are used in conservation projects in Bam Citadel.