This study has been prepared by assessing students' level of readiness to school about the subjects of Language, Psychomotor, Affective, Social, and Cognition developments and to support the development of students who are incapable in those fields of the first grade students who started primary school. The Kiel Test of Admission to School has been employed in this study to assess the level of readiness of newcomers to primary school. After the pre-application of the test, individualized supporting educational programme has been applied to students who are incapable in the fields of language, psychomotor, emotions, social, and cognition. After the supporting educational programme, the final application of Kiel Test of Admission to School has been applied and the effects of educational supporting on the development of children have been discussed. In the pre-application of the Admission to School, the research group consists of 10 students chosen randomly from primary schools in Bolu through the method of sampling among 87 first grade students who started primary school. The study has been carried out as an action research. The data of the research have been analyzed with the descriptive content analyze, which is used in qualitative research. At the end of the research, positive developments have been observed who had inability and/or lack of knowledge during the pre-applications. Therefore, this study can be regarded as an effective operation. It is thought to prevent barriers to learning that caused by individual differences through this kind of study. (Contains 1 table.)