Abstarct: Nowadays, transmission and retention of fuels, water and other energy resources by buried pipes, tanks and cables in urban and non-urban areas are necessary. This leads to creation of huge and costly underground networks. Following creation of such networks, a matter that has special importance, is maintenance of these human-made installations to prevent them from possible destructions. These unseen destructions to the installation, located in the subsurface shallow areas, may be made, which can cause considerable financial losses and also irreparable environmental contaminations. In this regard, we can use geophysical methods for maintenance of these installations. Often there is a sufficient physical contrast between these installations and their surrounding media. Thus, these installations are suitable targets for detection by GPR method. In this research work, the processing and interpretation of GPR data acquired from the GPR survey on buried pipes including mextallic pipes used for gas transmission have been carried out. To find advantages and disadvantages of GPR method, we have compared the GPR results with the results of processing and interpretation of magnetic survey on the same targets in the study area. As a result, GPR method has higher resolution in comparison to magnetic method. However, GPR waves in subsurface media having high electrical conductive are intensively attenuated, and hence, the depth of penetration in this method is limited. As can be seen from the GPR depth sections obtained from the survey area, the depth of penetration is even less than 2 meters. Magnetic method, despite its weak resolution, can detect the targets in high electrical conductive media more successfully compared to GPR method if there is a good magnetic susceptibility contrast between the target and the surrounding medium. In urban areas, where high noise levels exist, magnetic surveys cannot successfully be performed, while applying GPR method using shielded antenna in such areas can have acceptable or even good results. A GPR survey can also be performed on a grid leading to producing three-dimensional (3-D) maps that contain relatively accurate, reliable and abundant information from the subsurface targets in the survey area. In this research thesis, the detection of buried gas pipelines and other shallow subsurface targets by GPR method in Qaleh-Showkat area, that is approximately located 10 kilometers to the west of Shahrood city, has been investigated, and also, the GPR results have been compared with the results of the magnetic survey in the area. From this comparison, we can see that GPR method as a high resolution geophysical method in detection of small anomalies, located at shallow depths and near together, contain much better results. However, in some parts of the survey area in which their electrical conductivities are high, GPR method has not been able to detect the subsurface targets or anomalies due to high attenuation of the GPR waves in these parts, and in such situations, magnetic survey can have better results. In addition, in this research work, a GPR survey has been performed on a grid, and the acquired data has been investigated in a 3-D form. This GPR survey has been carried out inside the main campus of Shahrood University of Technology where high level of noise in the survey area, impeded us to run a magnetic survey in the area. Thus, in this area, we have not been able to obtain the magnetic results, and thus, compare the magnetic results with the GPR results, obtained from the GPR survey in the area. As a result of this GPR survey, the subsurface targets at different depths in 3-D maps have been detected with relatively good accuracy and resolution. These 3-D maps can considerably help the interpreter to interpret the GPR data results reliably and accurately. Moreover, significant and relatively comprehensive information from the subsurface is obtained. 3-D presentation of the GPR data results is very useful in the 3-D visualization of the subsurface, and thus, can indicate the targets more sensibly.