The aims of this study was to definite the eighth grades of the students both of the concepts of identity and equations, provide a sample, to investigate come across the problems experienced while the relationship between these concepts was being inquired. Survey model was used in this study. The data was obtained by using Concept Information Sheet (CIS) in fall semester of 2011-2012 academic year, primary schools 242 students attending in the grade eighth class, a mid-sized cities in terms of population in the Central Anatolia Region. The data was analyzed by descriptive method. It is determined that students have difficulties on “definition of identity "," definition of equation", “giving an example on the identity and the equation", and" Is there a relationship between the equation and the identity?”. The key role of the concepts of identitiy and equation on mathematics especially on analysis and algebra was emphasized. As a result, the students have been identified some difficulties on which the comprehension of the basic mathematics concepts such as identitiy and equation. In addition, these concepts are confused with each other and they have some misconceptions.