The objectives of this research are to know the students’ difficulties in translating the socio culturally-bound Expressions in Indonesian- English translation, and to analyze the cause of the students’ in translating the socio culturally-bound Expressions in Indonesian- English translation. The researcher analyzed those phenomena based on the consideration of the students’ problem in translation investigated in the process of pre-survey. Therefore, it is hoped that this research is beneficial in illustrating the phenomena of translating the socio culturally-bound expression. The method of this research was qualitative research in the form of a case study carried out at IAIN Metro. The primary source of this research is the translation assignment result of the students’ of IAIN Metro in academic year 2020/2021. The total numbers of the students’ are 20 students. The researcher uses documentation and interview in collecting the data. The documentation was conducted to know the students’ difficulties in translating the socio culturally-bound Expressions in Indonesian- English. The interview was conducted to analyze the cause of the students’ in translating the socio culturally-bound Expressions in Indonesian- English translation. The research results show the students’ translation of socio culturally-bound expression in Indonesian- English translation that consist of that consist of 85 % inappropriate use of socio cultural bound expression and 15% appropriate use of socio cultural bound expression. In addition, the second research result is about the causes of the students’ difficulties in translating the socio culturally- bound expressions in Indonesian- English translation caused by the translator's lack of knowledge in both languages in general and in the significance of the functional equivalence in particular, limited linguistic competence, their poor pragmatic competence in the target language, lack of cultural awareness and lack of cultural interaction and experience.