Manifestations of the Sasanian period’s artistic influence are abundantly evident in the eastern territories of this empire through archaeological discoveries and surviving artifacts. Among these, the designs on a box known as a śarīra reliquary, discovered in a Buddhist temple within the Subashi site in Kucha city, Xinjiang Province, western China, illustrate a fusion of Sasanian, Buddhist, and local artistic styles. 1 Accordingly, the present study aims to introduce and analyze the motifs of the aforementioned box, thereby addressing the following questions: 1. Which Iranian-Sasanian religious beliefs are reflected in the motifs used on the box known as the śarīra reliquary? 2. Based on the motifs of the śarīra box, what are the primary designs and themes that constitute the artistic influence of Sasanian-era Iran on the regions east of the Iranian plateau? Based on the proposed hypotheses, the motifs employed in the śarīra box reflect the most prominent religious and symbolic elements of the Sasanian period; elements whose examples can be observed throughout the Sasanian realm, Central Asia, and China, particularly along the Silk Road trade route. Sasanian art and religious beliefs found their way into China through trade exchanges, the gifting of royal presents, and the migration of Sogdians and other Iranian-speaking peoples, influencing the artistic works of those regions. The Kucha region, due to its specific geographical location in the Tarim Basin along the Silk Road in western China, was considered one of the most frequented and caravan-laden cities. Consequently, this region witnessed the formation of Buddhist temples and grottoes, an increase in the arrival of caravans and travelers, and, subsequently, the presence of artists, musicians, and other social strata of that era. Kucha gradually transformed into a city where music held a high status, and various Iranian musical instruments, such as the vertical harp and the barbat (lute), were widely played. As a result, Kucha can be considered one of the best places to study the influence of Sasanian art on Chinese art. Despite the significance of the topic, no independent research has yet been conducted on the Sasanian-Iranian elements present in the motifs of this box. The present research is theoretical in nature, conducted with an analytical-comparative approach, and its data collection was carried out through library research and the utilization of available resources.