The Keriyas of Xinjiang are mainly distributed in Yutian county and Daliyabuyi township in the southern route of Xinjiang Uygur Autonomous Region along the Land Silk Road, and the ethnic costume culture is more obviously influenced by trade, religion and multi-ethnic cultural exchanges. Keriya females’ ethnic costumes, in particular, have distinct regional characteristics, and a complete set of costumes consists of four parts: a headscarf (yāghliq in Uyghur), a small decorative hat (tälpäk in Uyghur), outerwear (pirijä in Uyghur) and an inner robe (yaqilighan kängläk in Uyghur). When dressing, Keriya females first comb their hairs into two braids, put on a white headscarf (yāghliq in Uyghur), and pin a delicate sheepskin cap (tälpäk in Uyghur) on the right side of the head. Of the white silk or cotton inner robes (yaqilighan kängläk in Uyghur) with purple pointed arc-shaped strips to decorate the right side of collar, some are sewn with cloth bands, and some are embroidered with silk threads. As they are made for interpreting something different, the quantities of decorative strips on each robe may vary. The bottom of the robe collar is usually embroidered with goat horn patterns and floral patterns, and the two sides of the collar are decorated with tasseled rope bands. The outerwear (pirijä in Uyghur), also known as the “arrow costume” (refering to the costume decorated with arrow patterns), is often made of dark silk with a sky-blue rim, with seven sky-blue arc-shaped and pointed strips decorating the chest symmetrically. The overall dress gives a sense of dignity and elegance. In a word, it is of great significance to study Keriya female’s ethnic costumes for further information of the plurality and coherence of costumes in this region. Based on the historical fact that the Land Silk Road has a profound influence on this type of costume, we firstly combined the methods of physical research with literature research to sort out physical and literary evidence of Keriya people and their costumes in the historical context of the Land Silk Road. Then, after deducing the costume origin and evolution from the three aspects of fabric, form and pattern respectively, which are linked to the evidence above-mentioned and characteristics of the existing costumes, we analyzed the multiformity and historical coherence of the costumes. The results of this study show that: the selection of clothing fabrics is dominated by the mulberry history that has existed and continued in southern Xinjiang since as late as the 3rd century and the patterns are dominated not only by the twisted branch and flora patterns from the Ming and Qing Dynasties, but also by the Islamic patterns with geometric features. As for the costume colors, they are both religious and ethnic. Sky blue and purple are added to black and white that represent religious connotations for highlighting ethnic identity. The costume forms, such as pirijä and yaqilighan kängläk, can be traced back to 5 000 years ago. The pirijä is in line with the Chapan originated from the nomadic people in the northwest, gradually developing from the fatigue dress to ceremonial costume. And the form of yaqilighan kängläk probably originates from the Eurasian through-head clothing, and is very close to the current Arabian robe under the influence of Central Asian costume culture. As for head dress, the yāghliq was commonly used at least in the Ming Dynasty. And the origin of the tälpäk is still uncertain, but its form is unique to the nation that has formed a set of folklore rules agreed upon within the group. It is worth mentioning that the combination of various types of clothing reflects the perfect combination of practical and aesthetic functions. The last point, in terms of costume decoration patterns, they reflect the background of multi-faith and multi-civilization exchange. The goat horn pattern appearing on yaqilighan kängläk is regarded as a symbol of fertility worship and is a traditional pattern that has been handed down for a long time. The curved decoration on the right collar of yaqilighan kängläk is related to fertility, too. The curved decoration on the chest of pirijä may have originated from the double-wing pattern brought by civilization exchanges.This study deciphers the origin of Keriya female’s ethnic costumes in the context of the Land Silk Road. Through the details of costume fabrics, forms, patterns and so on, the evidence of multicultural exchange and the shaping process of clothing in the historical process are presented in the backward induction. Exploring the specifics of the costume culture deeply influenced by multi-ethnic exchanges and multiple religious transformations is important to promote the study of Uygur’s ethnic history and culture. To some extent, this study may also offer a little insight into the history of the world along the Silk Road. [ABSTRACT FROM AUTHOR]