Buddhist Texts written in Chinese are important data not only for studies of Buddhist texts but also for studies regarding the history of the Chinese language. Seonmun Yeomsongjip (hereafter SMYSJ), a book compiled by monk Hyesim during the Goryeo era, is the oldest and largest Buddhist scriptures in the nation and has always been one of the must-reads in the Buddhist community. This Zen dialogue-type SMYSJ which details quotations by founders of religious sects has many interrogative sentences. From such an aspect, this book is highly valued as precious data for studying colloquial words during the Song Dynasty. However, there have not been many linguistic studies with regard to this text. Considering that there are plenty of interrogative sentences in SMYSJ, for this study, efforts were made to understand the patterns of development of interrogative sentences based on an analysis of the kinds, types, and frequency of interrogative sentences that appear in the book. Based on this kind of analysis, interrogative sentences appearing in SMYSJ can be divided into six categories. The ‘何’ category, which has the largest number of lower types and is used the most frequently, has been used in the forms of 如何, 云何, 若何, 何物, 何者, 何等, 何处, 何方, 何所, 何在, 何人, 何故, 何以故, 因何, 何以, 以何, 作何, 何似生, 何时, and 如何 has enjoyed the highest frequency of use. The ‘什么’ category of the second-highest frequency of use contains the forms of 什麼, 什麼生, 什麼处, 什处, 什麼人, 什麼时, 什摩时节, 作什麼, followed by the ‘怎么’ category to which the forms of 作麼, 作麼生, 作生, 怎生 belong. An interrogative pronoun of the fourth-highest frequency of use is the ‘怎么’ category to which the forms of 作麼, 作麼生, 作生, 怎生 belong, followed by the ‘那’ category with just three forms of 那箇, 阿那箇, 阿那个, and the ‘几’ category with 幾箇, 幾何, 多小, 大小. In the ‘几’ category, 大小 appeared most. Regarding the study on the usage of interrogatives, those interrogatives for asking men, things and places were connected by type and their semantic functions were analyzed. According to the analysis, each type had very different forms of expression, but there were significant differences in terms of frequency. Regardless of types, most of the interrogatives appearing in SMYSJ were used in interrogative sentences. A considerable proportion of them, of course, were used for rhetorical questions but some of them were used for directing. In conclusion, regarding interrogatives appearing in SMYSJ, expressions used for colloquial words during the Song Dynasty appeared, but some types of usage during this period did not appear. Considering these aspects, interrogatives appearing in SMYSJ did not have the complete features of the modern version of the spoken language.