Abstract In order to investigate the pattern of the changes of blood supply of the vascular superthin skin flap during expansion, in 17 patients, under the subdermal vessel networks layer of the periauriclar area, an expander was placed, and the skin was preliminarily expanded. The changes of blood supply were found regular: When the injected fluid volume was excessive, the skin became pale or cyanotic, the skin showed congestive telangiectasis. If great care was given during the procedure, the expanded skin could pass safely through the stage of poor blood circulation. The expanded superthin skin flap were applied in auriculoplasty in 17 patients. The results included 3 failures, and 14 satisfactory.