At Le Thanh Hien High School located in Vietnam, the students are not good at English. They can pass their exams easily but they find it difficult to use English to communicate. To help the students improve their speaking skills, it is necessary for their teachers to find ways to help them overcome their problems. Moreover, the teachers need to know the factors that affect their students’ speaking performance so that they can deal with these factors to help the students improve their speaking performance. However, until now, there is no research conducted at this school about these areas (Tuan and Mai,2015).