The process of developing electronic information resources is critical as it is the basis of meeting the users' needs and accessing electronic resources. Therefore, the process should involve right principles and clear foundations to be followed. This study aims to identify the reality of the electronic resources (ER) development at Sultan Qaboos University (SQU) libraries, to understand to what extent libraries have committed to the main principles of development the electronic resources, and the effect of using E-resources on the continuity of development and their utility. The study adopted the mixed-method approach that combines quantitative and qualitative data. Content analysis approach was utilized to analyze documents of NISO (2007) and IFLA (2001) principles to develop a checklist of the main principles of electronic information resources development. The simi-structured interview was used to collect detailed and in-depth data of the reality of the electronic resources development and their principles. There were six interviews with staff who are taking the role of developing electronic resources at SQU. While statistical reports were used to identify the usage of electronic resources, and the effect of using E-resources on the continuity of their development. The findings show that the development process is central and has been carried out in the main library since its beginning subscribing to electronic resources in 2000. The main library hasn't a written policy related to the mechanism of E-resources acquisition. The study revealed that 85% of NISO (2007) and IFLA (2001) principles are followed at SQU libraries. There are availability and use, intellectual property, information security, maintenance and training, operability, and integration with electronic operating systems, The study shows that rate of using ER in 2017 has increased to 533% than it was in 2014. Also the download rate in the Arabic databases increased by 274%. The training programs and marketing campaigns cause these indicators. On the other side the rate of download in E Journals, E-Books and E-Theses are decreased as following: 22%, 53% and 28% than in 2014. Because the users preferred to use the bibliographic databases than to get E-Books, Journals or theses directly. As a result of these indicators, the university libraries continue to keep some of the electronic resources and unsubscribe others. The study concludes with a number of recommendations such as stating a clear policy to develop electronic information resources, organizing training courses especially for those who taking the role of dealing and negotiation with vendors in the new trend in electronic resources and methods that can be developed to understand the needs of users. Finally, negotiation, library consortium, and the open access resources can be used as ways to avoid the high cost of electronic resources subscriptions