Many students feel difficult in learning English. One of causes is level of their conviction of learning English are less, so that the motivation in learning English is diminish. Among all other subjects, English subject is a foreign language for student. Therefore, the students were demand to seriously in learning English. Self-efficacy is one of the psychological aspects that can influence students’ motivation in learning English. Self efficacy is an important factor to start any action especially for learning English. Therefore, recognize the students’ self efficacy in learning English is very important for an English teacher in order to easily in giving the appropriate treatment for them. In this regard, this study aims to find out is there the effect of students’ self efficacy toward students’ motivation in learning English. The respondents of this study were 40 students from the first grade of SMAN 1 Simpang Tiga. Within a descriptive research model, self efficacy questionnaire was applied to the forty respondents. The collected quantitative data were analyzed by SPSS 16.0 for windows. The simple linier regression was used to analyze the data. The finding of this research showed that score of t test = 7.402 > t table = 4.304 with the significance score 0.00< 0.05, so Ho is rejected and Ha is received, it means there is a significant effect of variable X toward variable Y. The result explained that there is effect of students’ self efficacy toward students’ motivation in learning English.