After the High Tang period the creation of Buddhist grotto images in China was gradually shifted from the northern Central Plains to the southwest regions and continued to flourish constantly down to the Song period.As a result,Sichuan became the key region of researching into the grotto images creating art of the High Tang to the Song periods.Thanks to its special position and the outstanding role of its Jinniu Road,Guangyuan functioned as the"fore-port"for Tang Buddhist art to be spread into Sichuan.Previously little attention was paid to Guangyuan grotto images in academic circles;and researches in this field stayed at the initial stage.Based on a large amount of first-hand material from surveys and using the archaeological typological method with literal records taken into account,the present paper makes a study of the periodization of the Tang grotto images discovered in Guangyuan. Creation of grotto images in Guanyuan was swiftly developed after this area entered the Tang period.During the whole Tang Dynasty,it underwent three phases of development:The first phase was from the beginning of the Tang period to Wu Zetian’s reign,when Guangyuan saw the first height of grotto opening.The second phase lasted roughly from Ruizong’s reign to the 10th year of Xuanzong’s Tianbao reign,when Guangyuan grotto image creation was in its prime.The third phase ranged roughly from AD 750 to 850,when this art showed obviously a declining tendency.The first phase can be further divided into two stages,which cover roughly the Wude and Zhenguan reigns and the Gaozong and Wu Zetian reigns respectively.From about the mid 9th century,grotto image creation in Guangyuan came to its thorough fall.The direct factors of this were that there was no extensive surplus cliff-sides suitable for opening grottoes and making images and that the heart of grotto image creation in Sichuan was moved southward from the mid and late Tang period.