Abstract: Effie Louise Power is known as the pioneer of the American library service to children. She dedicated all her life to the library service to children, writing the first teaching materials, promoting professional education in the field, committed to children’s literature creation, and promoting the development of library storytelling activity. “Book and children are the foundation of library service” “providing the right book for the right child” “library service to all children” “selection, but not censorship” are the service philosophies that Power advocated, which becomes the essence of children’s librarianship.

Key words: Effie Louise Power, Library service to children, United States