Vietnam has a reputation for being a successful nation in preventing the Coronavirus disease (COVID-19) outbreak in 2020, with a lower number of illnesses than other ASEAN countries. However, to ensure that students are safe and informed about the coronavirus outbreak, Vietnamese higher education has developed online learning (OL). During the COVID-19 epidemic, this paper explores the relationship between elements such as learning readiness, learning strategies, and learning performance in the Vietnamese OL setting. Four hundred undergraduate students were randomly selected from Hong Duc universities, and Saigon University participated in this study in different zones. Analyzed data has applied structural equation modeling (SEM) using partial least squares (SmartPLS-SEM). The findings found that Vietnamese students were much more likely to believe in interaction in OL, to feel comfortable using a computer with their computer efficacy, and to have confidence in communicating in the digital environment, all of which were important variables in assuring the success of using OL. The factors of "motivation" and "test preparation" show a poor relationship with learning performance. Therefore, the OL process in Vietnamese, on the other hand, needs to be more inventive, with a greater focus on lecturers' awareness and practice of online teaching pedagogies such as motivation, techniques, and test arrangement. During OL, students' readiness in terms of learning control, self-directed learning, and engagement must be considered and supported.