Students’ Assessment is one of the teaching practices which most affect into learning and development of students, especially because it determines their present and future life. Numerous studies have demonstrated the relationship between how teachers assess and their conceptions about teacher’ assessment. As a result of its importance, the study of assessment’ conceptions has gained strength in recent decades. Therefore, the present study seeks to deepen into the present studies that focus on knowing the conceptions about assessment. To achieve this goal, we have structured the paper into three parts. Firstly, we delve into the definition of conceptions and their concreteness in the educational and evaluative field. Secondly, we review the group of researches on assessment’ conceptions in four directions: a) types of conceptions, b) factors that affect this diversity, c) the relationship between conceptions and assessment practice, and d) other studies related to conceptions. Finally, we close the present work with some personal reflections about what we have learned from the studies analyzed related to assessment’ conceptions as well as to propose future lines of research centered on what still remains to be known about implicit beliefs of students’ learning’ assessment.