Purpose: The aim is identification and ranking of influential factors in site selection for public libraries.Method: In this study, as a practical research, combined survey methods (descriptive-analytical) are used. In order to identify the influential factors in site selection for public libraries, with library, archival studies and consideration researches, conducted in the field, identified influential factors. Then, a questionnaire was used to collect experts viewpoints. The rank of influential factors designated by distributing another questionnaire. In order to calculate the results of the paired comparisons of criteria and indicators extracted expert Choice Software in order to analyze the spatial libraries with the chosen criteria, and identify new areas Arc GIS Software were used.Findings: The results indicated that respondents view the importance of the criteria are different. The public library location was identified through 34 indexes in six main criteria of centrality, compatibility, and predictions of future facilities, library local orientation, physical conditions and the competitors. Conclusions: Assigned points based on 13 indexes of the low correlation, 12 indexes of the average correlation and 9 indexes have a high correlation. The variable that had the highest weight in each group was determined and the model of the factors presented locate public libraries.