The purpose of this thesis is to describe the axiological principles of Maria Montessori's educational system in primary education. The emphasis will be on her educational methods that are present in primary education, whether they are Montessori schools or public schools that have taken over part of Maria Montessori's educational system. She is the first Italian female doctor and founder of the Children's Home in Italy. Her didactic material is very important in the teaching process because it represents the educational system of Maria Montessori. She also worked with low-income children and included them in educational work. Maria Montessori most advocated her principle of "Help Me Do It Alone". Her division of the child's development is by age, so her periods have sub-periods. Throughout each period, different types of child development in a particular period are described. The second period is most important for the topic of diploma work, because then the children are present in the classroom. The students to whom her pedagogy was applied were more inclined to work individually and make independent decisions about certain teaching contents. Due to her didactic material, students had greater imagination and freedom to choose activities during the teaching process. Montessori schools are present outside the Republic of Croatia, and the Republic of Croatia established a Montessori Primary School in Zagreb. There is also special education for Montessori teachers. Each axiological principle of Maria Montessori's educational system will be explained through classroom teaching. At the same time, the reasons for accepting the Montessori solution in public schools by parents, students and teachers will be outlined, as well as the objections to its primary education system. Most complaints were about formalism, a negative attitude to fantasy and fetishism.