The Yungang Cave Complex in Shanxi province is one of the largest Buddhist sculpture repositories produced during the Northern and Southern Dynasties. This thesis argues that the iconographic evolution of the Yungang caves underwent three developing phases which can be summarized as the five Tan Yao Caves phase, the transitional period, and the sinicized third-phase under the reigns of five Northern Wei (386-534) emperors Wencheng, (452-465), Xianwen (466-471), Xiaowen (471-499), Xuanwu (500-515) and Xiaoming (516-528).

This dissertation studies the Yungang third-phase caves, namely those caves executed after the capital was moved from Pingcheng to Luoyang in the year 494. It focuses primarily on what we call the western-end caves, which are composed of all the caves from cave 21 to cave 45, and as cave 5-10 and cave 5-11 are typical representations of the third-phase and even today are well preserved, they are also included in this study.

Using typology method, as well as primary literary sources, this study places the western-end caves in their historical, social and religious context while focusing on four perspectives: architectural lay-out, iconographic composition, subject matter and style of representation. It deals with such questions as: what these images represent, what is their connection with Buddhist literature, what is the origin of the style of the western-end caves, what is the relationship between sculpture and painting, what is the relationship between the monastic life and Buddhist art, what was the status of Yungang after the transfer of the capital to the south, and who were the patrons. This study sheds new light on the changes in the iconographic motifs over the time from the first-phase to the third-phase and constructs a timeline for the sequence of construction of the western-end caves.

The study also investigates the iconographical inter-relationship between the Yungang third-phase caves and those in the Longmen and to a lesser extent, the Gongxian complexes, as well as some relatively small caves in Shanxi province in order to trace the spread of the "Yungang Style." This will map out the evolution in Buddhist iconographical style throughout the Central Plain of China.

Although the caves of the first two phases have been studied extensively, this study is the first comprehensive examination of the Yungang third-phase caves. It is also the first investigation of the interrelationship between the Yungang style and that of other sites such as Longmen and Gongxian, as well as individual caves in the Shanxi area. This work is based on a broad consultation of primary text material and, most importantly, on first hand site observations by the researcher, which are documented by an extensive photographic record.