The present research study provided a detailed description of needs analysis (NA) of Law and Social Science institute, UIA students in relation to the English education requirement. English taught for law purposes is known as English for specific purposes (ESP). The main objective of the study was the development of an ESP curriculum for Law and Social Science Institute students at the University of Internal Affairs (UIA), Mongolia. The researcher of the study utilized a Google form platform which contained a collection of both qualitative and quantitative research data. The study was conducted in the Law and Social Science Institute, UIA based in Ulaanbaatar in the academic year of 2021-2022. Participants of the study included 128 current 1-4th course students. The data were gathered utilizing semi-structured interviews and a researcher-made questionnaire. Through NA, the researchers analyzed the learners’ factors, present situation, target situation, and specialist discourse of the population. The results of the study were used to design and develop an ESP course curriculum for students studying in the Law and Social Science School of UIA.