This publication of the "Ritual for Expelling Ghosts", based on the manuscripts used by the "bimos" (priests) of the Yi nationality in Liangshan prefecture, Sichuan province, counts as a world premiere. The religious system of the Yi of Liangshan is the subject of a very limited body of scholarship. Even if, in recent years, the number of publications in Chinese has rapidly increased, standards of scholarship and coherent sets of working hypotheses have yet to be established. One of the main limitations to further research is that a scientific edition of primary sources remains virtually non existent. This is why the Ricci Institute feels especially proud to publish this Yi Chinese edition of an all important religious classic, which also belongs to the world treasury of popular literature. The Chinese introduction written by Bamo Ayi will provide the reader with background information on Yi ritual books in general and the Ritual for Expelling Ghosts in particular. This preface aims at putting these data within a broader framework of understanding.