The purpose of this paper is to consider the formation of PTA. The direct ancestor of the National Congress of Parents and Teachers is the National Congress of Mothers. The National Congress of Mothers was organized by two women of Alice M. Birney and Phoebe A. Hearst in 1897. The president, Mrs. Birney declared the object of the Congress is to educate mothers at first convention. 11 years later, the Congress changed its name to the National Congress of Mothers and Parent-Teacher Associations. And more 17 years later, the Congress changed its name to National Congress of Parents and Teachers again. The question now arises : Why did the Congress need to change its name? This question drives us to examine of the parent-teacher relationship, and to relate its relationship to educating mother.