Traditional Yi society is a patriarchal one in which men were believed superior to women.For thousands of years,female genders,who should have been equal to male genders,have been shackled in the patriarchal society's net and in the dominated and ruled position and had no right.Mum's Daughter is an outstanding Yi folk long lyric poem,and from analyzing the text we can find that male and female genders are different in the social status,division of labor and leading right in society,and sexual equality is human being's perpetual ideal to seek for.