The concept of null curriculum was first introduced by Eisner (1979). In his view, what is deleted from the school curriculum leads to educational defects in learners. The incidence of educational defects is not primarily due to the omission of some of the educational components, but there are other causes for null curriculum, such as neglected, demoded, distorted, and sterilized curricula, which also lead to shortcomings in the education process of individuals (Marzooghi, 2015). The present study investigates and validates conceptualization of various types of null curricula in both intentional and unintentional dimensions and also at the intended, implemented, and learned levels of curriculum. In this regard, the case analysis was used for determining the, and Cronbach's alpha coefficient was employed for obtaining the validity of the findings. The findings indicated the reliability and validity of the types of null curriculum.