Turk itself is not the name of a place but originally that of a race. Turkistan is the name of the land where Turkic stock settled down, corresponding to Central Asia in a narrow sense and referring to ‘a country of Trukic people’. The two Turkic empires that played central roles in Turkicizing Central Asia were the Türküt Empire and the Uyghur Empire, which were of the same Turkic stock. I have mainly observed the costume of the above two Turkic empires. As for the Türküt Empire, I have focused on the most flourishing period from the 6th to the 8th century; as for the Uyghur Empire, I have observed costume materials centering around the 9th - 14th century of the west Uyghur after the movement to the west from the north Gobi desert. The research results are as follows. The Türküt costume, according to the Chinese historical record, includes some typical properties. The Türküt had their hair braided into several parts and flown loose at the back, the so-called P'eifa; wore a turn-open-collared coat hanging down as low as it reaches the ankle; adjusted their clothes to the left as well as to the right; wore a belt decorated with gold and silver, with things like knife, sword, etc. tied to it; decorated themselves with gold earrings, hanging glass ornaments, etc. Uyghur costume includes practicing P'eifa and wearing various types of crowns reflecting the status. Those with a higher status tied a red silk string under their chin. Males wore a round-collared, fitting-sleeved long coat and Diehsiedai on the waist, with things like knife, awl, towel, and acupuncture needle box tied to it. In the later period, they wore a round-collared, fitting-sleeved long coat as in the earlier period, with the front part, the hem, and sleeve edges decorated with stripes. It is noticed that the decorative aspect was stressed on the belt from the fact that two stripes of a silk band hang down in its front central part. Both the Türküt and the Uyghur practiced P'eifa and wore a turn-open-collared, fitting-sleeved long coat and Diehsiedai on the waist. But the Uyghur always wore a crown and their status was distinguished with the type of the crown. As for the belt, while the Türküt tied weapons, the Uyghur practical utility goods. Toward the later period, however, a change is observed such that the formal and decorative aspects of the belt were increasingly stressed.