The aim of this research was to find out the most dominant psychological factors of students’ inability to speak English in EFL. This research was conducted at Second Grade Students of SMK Muhammadiyah 1 Purwokerto in the Academic Year 2017/2018, Moreover, 27 students was taken as a sample of this research. Questionaire and interview was taken as the instrument in collecting the data. After analyzing the data, it was found the most dominant psychological factor of students’ problem to speak English in EFL is lack of confidence with percentage or 63 %.