The present research aims to develop a theory on teacher-student interaction in the first year of primary school period. The present research was designed in grounded theory research which is one of the qualitative research traditions. A total of 18 primary school children started the first year of primary school. Data were collected through participant observation. Participant observation was launched after all necessary ethical permissions were taken from local education authority, the participant children, their teacher, and parents. Data were analyzed through constant comparison within three stages as open coding, axial coding, and selective coding. It was reported that the teacher and the first graders mutually developed strategies and there were several circumstances in the interaction that nested behavioral problems.