English has become a global language and English speaking skill plays an important role in order for people's communication to fit into the real world. Motivation is regarded as an influential factor in the success of any activity, including learning English speaking. This research aimed to analyze the factors influencing students’ motivation to learn English speaking. The study involved the participation of 42 English majored sophomores at a private university in the Mekong Delta of Vietnam. The collected data from a questionnaire and an interview show that factors from students, classroom environment, factors from teachers, and students’ other relationships in learning English speaking motivated the students during their learning English- speaking process. The research findings could contribute some insights into motivating teaching and the improvement of English teaching and learning quality.