Purpose: The aim is investigating views of three groups of library users (non-professionals, specialized professionals, librarians)  regardingthe importance and value of Attributes of entities of FRBR Conceptual model in supporting user tasks.
Methodology: all attributes of entities of FRBR Conceptual model in supporting user tasks, was examined and evaluated through a descriptive-survey of the views of potential users of OPACs. During the data gathering sessions, semi-structured interviews were conducted to collect information from the research population for valuation of each attributes of entities in supporting user tasks with the questionnaire prepared by researcher based on IFLA FRBR report.
 Findings:, “title of work”, “title of expression”, “title of manifestation”, “name of person” and “name of corporate body” are the attributes all users  assigh them  being of great value in supporting user tasks.
Originality/Value: it is necessary that library software be reviewed based on FRBR conceptual model. Also because little research of users' point of view  isstudied t more researche is needed. According to IFLA FRBR group,has confirmed this.