The purpose of the study was to articulate the Librarians' Individual Abilities affecting on applying the social networks, as a tool for marketing, from viewpoint of librarians working at the Iranian state university libraries. This research was analytical survey research. The research community consisted of 146 librarians who are working at central libraries of 40 state universities in the capital of province affiliated to Ministry of Science, Research and Technology. Data collection instrument was a researcher- made questionnaire. The findings of the research confirmed the impact of librarians’ individual abilities on the usage of social networks as a marketing tool in academic libraries. Among the components, “skill for establishing a communication via a social networks” (3.34), “familiarity with social network” (3.26) and “cognitive skill for meeting users’ information requirements” (3.13) had the greatest impact on using social networks as a marketing tool in academic libraries. Based on the findings of the research and outputs, we concluded that, individual abilities are among the most important success factors of academic libraries and most be defined as an important element of academic librarians’ competency profile. For that, library managers and librarians are to be aware of the ever-changing conditions in academic libraries, and assess the strengths and weaknesses of individual librarians' characteristics and their job performance for effective use of social networks in library marketing.