Objective: To provide a statistical model of Iranian libraries. Methodology: The research approach is mixed. The background of library statistics in Iran and the world was identified, systematicly reviewed, and documentarily analyzed through purposeful sampling. By searching Persian and international leading databases with the keyword "Library Statistics", relevant sources were identified, and duplicates were removed as well as screened. 138 sources in Iran and 223 sources in the world were selected and evaluated. Then, library statistics data items were extracted from them. With the Delphi quantitative method, the statistical model items of Iranian libraries were validated and completed by unanimous sampling with the consensus of experts. Using grounded theory qualitative method, the theory of description and classification of the statistical model of Iranian libraries in the reporting unit, application, and measurement unit was done by interviewing the interviewees via sampling based on purpose and open questionnaire. By open-coding, the main categories of items and categories of the reporting unit, application, and measurement unit; with the axis, the relation of class and categories is extracted; and by selective, systematic development of the class and categories of the statistical model of Iranian libraries were presented. Findings: Information items of the statistical model of Iranian libraries were obtained by Delphi method. Information items of the statistical model of Iranian libraries included 59 items. Based on Grounded Theory, the five main classes of collections, services, human resources, financial resources, and infrastructure were underscored; The main class includes 22 itemes in collections, 14 items in services, 4 items in human resources, 11 items in financial resources, and 8 items in infrastructure; And the category of reporting unit responsible for collecting statistics of Iranian libraries in university, cooperative and network, public, schools, specialized, and provincial libraries; The application of statistical model of Iranian libraries in five levels: international, regional, national, provincial, and local; And the category of measurement unit including volume, title, added, holding, withdrawal, person, hours, Rials, linear feet, and square footage was identified and presented. Finally, the statistical model of Iranian libraries was drawn and presented. Conclusion: Statistical model of Iranian libraries can be utilized in order to create a system for collecting library statistics; and it is a basis for compiling the standard statistics of Iranian libraries. Based on the statistical model of Iranian libraries, library data will be upgraded from the quantitative level of the library directory to the level of library statistics. The statistical model of Iranian libraries is a tool for making decisions and attracting resources to the library. In fact, it provides a set of basic data for library reporting at various levels, and uses descriptive elements to provide a framework for comparing data using descriptions of common elements.