The convention of child's right as the principal instrument in protecting children has paid a momentous attention to the "Best Interest of Child" and the Committee on the Rights of the Child has introduced different dimensions of this matter in its general interpretations. The principle of "Best Interest of Child" is a matter implemented in all protective and development issues in regards to Children's Rights. The term of "Interest" in the convention has been used in a vague and general way thus can be interpreted in the appropriate way in diverse legal systems. the Committee on the Rights of the Child also certainly called attention to, is that children and their views should be taken into consideration in all programs and actions, including budgeting, developing programs and strategies and so on. The Committee's important recommendations are to safeguard the dignity of children in line with the principles of human rights and to refrain from coercive action against children. This research seeks to answer the fundamental question of what is the best interest of the child in accordance with international practice and international human rights law? Contemplation in the case law suggests that although it is difficult to discover the best interpretation of the child's interests, and especially in the jurisdictional and culturally diverse context, it is a function of the particular circumstances of each case; It will lead to a conceptual development of child rights and a minimalist understanding of the universality of its obligations in practice and theory.