The aim of this study was to examine the cognitive development, language development, social-emotional development, gross motor development, fine motor development and self-care skills of children aged 48-72 months in terms of various variables, with a reliable, valid, and norm-referenced developmental assessment tool based on parental views. Research; It was held with a total of 1099 participants, 304 between 48-53 months, 218 between 54-59 months, 270 between 60-65 months and 307 between 66-72 months from across Turkey. Personal information form and Selçuk Developmental Assessment Inventory were used as data collection tools in the study. At the end of the research, although the developmental areas vary in age groups, it was seen that they differed according to gender, attendance at pre-school education institution, total number of children in the family, mother's education level and father's education level.