Aim: In the present study, the internal (mental) and external (cognitive) characteristics of the children’s librarian were examined and then prioritized. These traits include competence in beliefs, feelings, emotions, and desires, and aptitude in speech and behavior, and are modeled on a philosopher named Nikolaus Tetens, who was Kant's contemporary. Methodology: The research was conducted in two phases and with two methods. The first (qualitative) phase included the analysis of internal and external texts and interviews with experts to extract the characteristics under the five categories, and in that, the theme analysis method was used. The second phase (quantitative) included the ranking of the extracted components with the opinion of experts, which Analytical Hierarchy Process (AHP) method, HP questionnaire tool and Expert Choice software were used. Findings: The findings showed that the components can be divided into three minimum, basic and ideal levels and the minimum level includes the most important criteria. At the minimum level and in the category of beliefs, knowledge about child literature and child psychology (Rank 1, 0.346), believe to priority of collectivism (rank 2, 0.265), understanding child’s sensibility (rank 3, 0.218), and believe to child’s rights (rank 4, 0.171) were among the most important components in the belief category. Psychic relax (rank 1, 0.385), being cheerful (rank 2, 0.213), enthusiasm for working with children (rank 3, 0.152), and having service mood (rank 4, 0.152) are among the most important components in emotive category. willingness to be accessible (rank 1, 0.429), self-motivation (rank 1, 0.314), tendency to work with households (rank 1, 0.168), and zest for change in environment (rank 4, 0.09) are among the most important components in volitive category; euphony (rank 1, 0.421), speaking and listening skills (rank 2, 0.228), persuasion and reasoning skills (rank 3, 0.225), and networking skills (rank 4, 0.127) are among the most important components in discursive category; ability to design area (rank 1, 0.324), bibliographic and technical service skills (rank 2, 0.266), person to person education skills (rank 3, 0.262), and ability to arrange decorate and dress (rank 4, 0.148) are among the most important components in active category. Conclusion: The findings show that the competencies of the characteristics and the practical skills accepted for the children’s librarian tend to be more collective than individualistic, and this is contrary to academic education, urban lifestyle, and social rules and regulations. Indirectly, they promote individualism. Therefore, in order to train librarians with these characteristics, it is necessary to teach self-learning methods, teaching methods, psychological and bibliographic knowledge, as well as trying to change their moral ideology towards socialism, collective interests and altruism. It is very difficult.