The goal of this study is So as to analyze the relevant primary cause of aspect of alopecia of women in their 20s∼30s which is the goal of this study, this researcher carried out experimental study design at the same time for making cross-sectional study design and analyzing the feature of hair. In this study, this researcher analyzed the questionnaires of total 416 persons and the hair of 71 persons by carrying out questionnaire and hair experiment at the same time on the persons who consented to this study and offered hair spontaneously for 26 days from Oct. 15, 2013 to Nov. 10, 2013, so as to analyze the aspect of hair loss of women in their 20s∼30s, primary cause to have influence on hair loss, and the feature of hair ofpersons who have hair loss and who don't have hair loss. And, the conclusion of study is as follows: Prevalence of hair loss of women in their 20s∼30s showed as 27.6%. So, it emerged that about 1 person has alopecia out of 3 women at same age. As for the primary causes to have influence on hair loss of women in their 20s∼30s, it emerged that family career promotes hair loss significantly with mental primary cause like stress, scalpdisease, and atopy as the result of recurrence analysis of multivariable logistic. As for the feature of hair of persons in thie 20s∼30s, it emerged that hair thickness of persons who don't have alopecia is thicker in comparison with persons who have hair loss. And, as for strength, it emerged that persons who don't have hair loss showed more tensility than persons who have hair loss. And, in case of persons to have hair loss, it emerged that hair snaps in the middle in pulling hair.