This final thesis deals with the topic "Diagnosis of class climate differences between two low-class schools". It´s divided into both a theoretical part and a practical part. In the theoretical part I define terms such as school class, class climate, class atmosphere and class environment. I also look at the main actors of the class climate, which are the pupil and the teacher. I´m also involyed in various diagnostic methods of class climate. The practical part is based on the survey questionnaire, using the MCI guestionnaire. The aim of this work is to diagnose the differences of these two low-class schools. Another aim of this work is to find out the climate differences of these two low class schools