Alopecia areata(AA) is a common dermatologic disease, the origin of which is still unknown. At least, it has been associated with some genetic influences in the etiopathogenesis. We have now evaluated AA patients to study the actual association of the genetic role by fingerprint analysis. The incidences of six or more arches were determined in 74 female and 86 male patients excluding alopecia totalis and universalis, and in healthy 167 female controls, based on Selmanowitz's thesis (1974). The results of this study are follows: 1. The difference between the frequency in AA patients(7. 5%) and in controls (3.3%) reaches the statistical significance(p<0.05 by x2-test). 2. The association of genetic background in AA is strengthened in the group of female patients(p<0. 01), recurrent episode(p<0.01). and multiplex farm (p<0.01). 3. Twenty patients(12. 5%) have family history. The incidence in 3(15.0%) of these patients is considerably common but not statistically significant. A correlation of biologic relevance and family predisposition in AA is not precluded. 4. The frequency of arches in patients and in controls is increased on both second fingers and decreased on both fourth fingers. It is more common on both second and left third fingers in female patients. The incidence of arches averages about 6 67% in patients and 4. 58% in controls.