Government had implemented the 2013 Curriculum for 5 years now, however, in practice, there are still a lot of teachers who haven’t fully comprehended this curriculum. Thus, it is intriguing to study “Junior High School Teacher’s Comprehension on Assessment System in 2013 Curriculum”. This study aims to find out the level of comprehension junior high school teachers have regarding the assessment technique in 2013 Curriculum. Furthermore, this study also tried to discern issues faced by teachers in implementing the assessment system in 2013 Curriculum. This study uses qualitative approach, and data were collected using questionnaires and focus group discussion (FGD). 5 sample locations were selected using purposive technique. The informants in FGD were 25 teachers and respondents filling the questionnaire were 4337 teachers. The result concludes that junior high school teachers’ comprehension on the assessment system of 2013 Curriculum is still low and not optimal. There are also several issues in the implementation. Recommendation proposed are for a strategic and detailed dissemination and training, and also a simplification of the assessment system in 2013 Curriculum, especially in assessment for attitude aspect and descriptive assessment.