The present article is a report on the preliminary results of the authors’ studies on the Western Xia (Tangut) inscriptions on the frescoes in the Mogao and the Yulin grottoes. The inscriptions, over 100 in number, were found in 38 grottoes, totalling over 1200 Tangut characters written in 232 lines. The number of Tangut inscriptions tops all those of the medieval inscriptions written in languages of other Chinese minority nationalities discovered in these grottoes. The. present authors translated them into Chinese and also made an analytical study of their contents.The distribution of the Tangut inscriptions in the two groups of grottoes is given in the accompanying tables. The reasons for the existence of this large number of them in these grottoes are explained historically from the Tangut’s occupation of the two Chinese prefectures Guazhou and Shazhou, and the Tangut people’s embracement of Buddhism.A large portion of the present article is given to the account of the religious activities at the Mogao and Yulin grottoes during the Tangut regime, the chronicle of the regime, its formal name as a state, geographical name, system of civil officials and military officiers,feudal titles, family names, and its language and script, from what has been learned from the contents of these inscriptions.The original Tangut. inscirptions and their trancription and translations are given side by side at the end of the present article for the reference of readers.