Site selection methods are currently underdeveloped in many countries around the world. In our country, although these methods have taken on a scientific dimension, but many aspects of it are still not considered during the research process. An example of this was the selection of the National Central Laboratory at Razi University, which in this study tried to examine the results by accurately understanding the spatial processes and then to generalize the differences in the results and compare them with other researches in other fields. Therefore, the initial methodology of this research included the selection of 18 effective criteria based on existing standards for laboratory location, whose maps were generated through GIS, and by selecting target criteria and setting scoring criteria in GIS, location maps were produced in 5 classes. . In the next step, the result was compared with the previous results of location and the causes of the disagreement were extracted and then by comparing the results with the published researches, the causes of differences were classified in the research results. The results show that there is a significant difference in the site selection in this study with previous university results; In this study, it is the best place to build a laboratory near the entrance of the university, while the previous choice was far from 600 m southeast of this place. This disagreement is due to the lack of attention to the spatial relationship between the selected location and the surrounding environment in determining the location criteria.