: This study aims to determine the understanding, implementation, and constraints faced by the teacher of Vocational High School State 1 Lhokseumawe in the implementation of the educational unit level curriculum. To achieve these objectives, this study uses descriptive qualitative approach. Data was collected through interviews, observation and documentation. The procedure of data analysis is data reduction, data display, and verification. While the subject of research is the principal, vice principal areas of curriculum and instruction, and teacher. The results showed that:(1) Teacher's understanding of the educational unit level curriculum has been positive and keep up with the needs of learners with attention to the weaknesses of the development of science, technology, and art as a whole and sustainable; (2) Implementation of educational unit level curriculum is done by adjusting the curriculum with lesson plans grains so that the delivery of teaching materials has alignment with the time and abilities of students; and (3) Constraints teachers in the implementation of educational unit level curriculum, among others: (a) lack of educational facilities and infrastructure that support the application for the establishment of educational unit level curriculum perfectly, (b) lack of awareness of the teacher in preparing learning materials before the learning takes place, (c) the lack of allocation of time in learning process, and (d) the lack of teacher supervision in controlling the achievement of student learning outcomes in the classroom and in the school environment development.