The present study, a slightly revised version of the author's 1968 Ph.D. thesis presented to the University of Chicago, investigates compound formation in Thai. Chapter 1 summarizes the transformational generative theory on which the study is based, discusses the concept that Thai is a "simple" language in comparison with English, and briefly outlines the structure of Thai noun phrases, Chapter 2 outlines the development of transformational grammar and presents the base component of a transformational grammar. Chapter 3 discusses the use of transformations and describes the transformational rules needed to generate the structures directly underlying the compounds themselves. Chapter 4, working from the assumption that most Thai noun compounds are derived from noun phrases in which sentences have been embedded as relative clauses, demonstrates how certain structures generated by the grammar proposed in the earlier chapters can be converted into Thai noun compounds. Compounds are analyzed by type. Chapter 5 is dedicated to the small subset of noun compounds considered to be learned compounds and offers solutions to the problems presented by such forms. [Document not available in hard copy because of marginal legibility of original.] (FWB)