Abstract: This paper describes and analyzes physical measurement data of Tibetans living inside Sanyan, a valley area between Gongjue County in Tibet and Baiyu County in Sichuan Province along the Jinshajiang River. The physical features of the Sanyan Tibetans can be described as :a tall stature; middle-distance skelic type ; super leptoprosopy; moderate nose size; and a normo-tensive blood pressure. It is believed that these Sanyan Tibetans belong to one of the Mongoloid subspecies found in North Asia, but because these people have some unique physical traits of their own, they are quite different from other Tibetan ethnic groups living around the Tibetan plateau as well as with other minority nationalities in China.

Key words: Tibetans; Sanyan; Tibetan-Yi corridor