Abstract: This descriptive study is a longitudinal survey. And it was done to assess the conceptual ideas about quantum concepts of high school students. Due to the length of the study, the population of the study consisted of all high school students in Tehran in academic year 2011-12 and in 2014-15. To assess students’ understanding of a concept, evaluation method was used. In this way, the options chosen in four categories: full understanding, partial understanding, misunderstanding and lack of understanding. Comparison of conceptual imagery about the concepts of quantum students in academic year 2011-12 with students in 2014-15 indicate that older students face more misunderstood, during the last few years, new graduates have understood better and this is the signs of changes in curriculum and curriculum development and better statement of the quantum content in new textbooks. Finding of this study showed new misunderstandings about the concepts of quantum. It is recommended that curriculum specialists, review school curricula to suit the existing misunderstandings.