Attachment is defined as an emotional bond established with the caregiver or people starting from the prenatal period, starting from the first days of the baby' s birth. The effects of these bonds with caregivers on children' s personality are explained by attachment theories. The foundations of attachment theory, which has an impact on individuals' entire lives from early childhood; It was introduced by John Bowlby and later developed as a result of their work with Mary Ainsworth. Ainsworth deepened the attachment with his experimental and observational studies. In this way, attachment theory has been supported by both experimental and observational studies. Attachment theory, based on early childhood years, is expressed by Bowlby and Ainsworth as the main regulators in interpersonal relationships. Attachment in early childhood is influenced by the relationships that children establish with person / persons or objects / objects, influencing their entire development process, and most importantly, plays an important role in the formation and shaping of their personalities. Therefore, the purpose of this study is to examine attachment in early children in terms of John Bowlby and Mary Ainsworth. For this purpose, by examining Bowlby and Ainsworth' s studies on early childhood attachment theory, in early childhood years; The relationships the children establish with their mother or primary caregivers are discussed.