The purpose of the study is to investigate how primary school teachers understand the concept of research-based teaching. The data is collected through qualitative research interviews and analyzed via life-world phenomenology. The study's overall conclusion is that teachers are complacent about research-based knowledge or exclude it from their teaching. The result shows five different dimensions; external, internal, relational, conscious critical and unconscious. The two categories of internal and relational dimension can characterize the meaning of teacher as researcher. These two categories show teachers understanding and being an example that a practice paradigm of research-based teaching is under development.