The government of Oman is attempting to bring modern technologies into its academic environment. One of the most important technologies is the virtual library. E-resources are not entirely deemed acceptable to be utilized in Omani higher education institutions according to the statistics that show a dramatic decrease in the use of (Masader) after the high usage at the initial launch of the project. This study aims to identify individual differences (ID) and system quality (SQ) determinants that impact the academics' acceptance of the Oman virtual science library (Masader) in higher education institutions in the Sultanate of Oman. Previous studies indicate that external variables play a crucial role in influencing the intent of the user to use e-sources. Based on this theoretical background, a group of external variables have been identified. Moreover, the study used the Technology Acceptance Model (TAM). A mixed-method was used to collect the data of 450 respondents from higher education institutions who are also members in Oman virtual science library (Masader). A set of non-parametric statistical methods in (SPSS) program were used to analyse the data after it had been ensured that the data follow the non-normal distribution. All the study questions were answered, and all the hypotheses of the study were proven. Briefly, the results revealed that academics have a high level of positive attitude towards the use of Masader, and a high level of intent to use e-resources in general. In addition, the results also revealed that there is a positive relationship between dependent variables and independent variables; and that the usefulness and easiness of Masader are considered to be an essential component, as the results of the linear regression test indicated that the effect of the external variables is stronger on the behavioural intention if it is through the indirect influence on the belief variables. However, the effect of the Individual differences (ID) and system quality (SQ) on the perception of easiness (POE) is greater than the effect on the perceived usefulness (PU). The study contributes as an addition to the body of knowledge and literature, especially in Oman, which was considered the first of its kind that investigates the factors affecting the willingness to use (Masader). Furthermore, the current study presents the evidence that attitudes are among the most important external independent variables and not dependent variables. On the other hand, practically, the study will contribute to the development of a useful road map for the various relevant groups (academics, decision-makers, researchers, information specialists, and librarians)