To explore the factors influencing on-line learning, the author sampled the students taking an on-line information technology course in a Hong Kong higher education institution and adopted a sequential explanatory design of mixed methods, in which a quantitative phase was followed by a qualitative phase. In the first quantitative phase, correlation and multiple regression analyses were used to examine the relationship between the potential factors and the students' learning performance. As a follow-up to have a better understanding of the quantitative findings, some of the students were interviewed in the second qualitative phase. The results of both phases reveal how the factors influence the students' on-line learning. These results provide good suggestions for on-line education improvements, and should be especially useful to educationists or any professionals who are concerned with the on-line education quality.