Xuanzang, who traveled to India by crossing East Turkestan, Central Asia and Afghanistan between 629-645, is known as a great traveler, translator and scholar. Xuanzang's life story and his visit to India were later written as a separate work by his students around 650. At the beginning of the XI century Shinku Sheli Tutung translated this work, which was written in Chinese, into Old Turkic/Uyghur in East Turkestan. In the 'Xuanzang Biography' written in the Old Uyghur script, there is some information about Old Turkish place names, peoples and history. One of them is the ethnonym Kyrgyz. In the part of the work where the skills of the Chinese emperor Taizong are praised, this ethnonym is mentioned in two places. In the first text, it is explained that Taizong fully researched Tibet, understood and knew the Kyrgyz completely, and that they were subject to China because he brought the right laws there. In the second text, it is described that the peoples of the north, including the Kyrgyz, came under Chinese rule. According to the general meaning of these texts, the Kyrgyz are a Turkish tribe that resides in the North of the Great Wall of China, which should be understood for China, that is, who they are to be known, and conquering them brings great prestige to China. [ABSTRACT FROM AUTHOR]