Abstract: Antithyroglobulin Ab(TGA),triiodothyronine (T3), antimicrosomal Ab(MQA) and thyroxine (T4) were detected in 36 patients with alopecia areata (AA), with 74 healthy persons as controls. TSH was detected in those cases with positive TGA and MCA. The result showed that the frequency of TGA and MCA in the patients with AA (19.4%) was significantly higher than that of the controls (4.1%) (P<0.01). It suggests that AA may be an autoimmune disease. In addition, the value of T4 in the patients with AA was lower than that of the controls. The cause remains to be investigated.