Library can be pleased with its activity if its collections and services are required by its users. To reach this level, it must meet several requirements related to users: to know users’ documentation and information needs, to possess knowledge in the various fields of science, culture and education, to be able to use information retrieval technologies, and to understand users’ profile and behavior. Data about users and their information needs helps to create better documentary products and services, to improve the activity of the library, and obviously to improve the fulfillment of users' information needs. In order to find out the users’ opinion on the activity of the National Library, a study was conducted, using the method of questionnaire analysis. This method allowed us to obtain accurate and valid data regarding users’ opinions. The questionnaire was applied during seven days. A sociological survey method was used because it is an effective and appropriate way of finding out the users’ requirements concerning the improvement of the library’s activity on the satisfaction of the interests expressed. The questionnaire was anonymous, and took on average 10 minutes to fill it in. The results were entered into a database, statistically processed and interpreted.