The purpose of this study is to investigate the nature of morphological structure of words in Korean and to examine the interaction of morphological properties with other components of grammar. In order to provide the adequate model for word structure of Korean, I adopt a morphological model which is proposed in recent developments in morphology (e.g. Lieber 1980, Williams 1981; 1981a, Selkirk 1982, Di Scuillo & Williams 1987). In this morphological model, some syntactic notions, such as certain notions of X-bar theory, a head of a word and argument structure are extended to the theory of word structure. Chapter 2 gives an overview of word formation models proposed within the framework of the lexicalist theory. Several word formation models of Korean are examined. This chapter also introduces some of the major theoretical assumptions upon which the analyses given in this study depend. In Chapter 3, the morphological properties of compounds in Korean are discussed. Two different sets of primary compounds are compared and the difference between them is argued to be attributed to the different word structures. The analysis of synthetic compounds is also given. It is shown how the word structure model which incorporates the Argument Linking Principle proposed by Lieber (1983) allows an adequate account of synthetic compounds. Finally, it is argued that the difference in internal word structures can make predictions on Sino-Korean tensification. Chapter 4 discusses the morphology of passive, causative suffixes, nominalization and the negative morpheme AN. An attempt is made to provide the lexical representations of passive and causative morphology using the notion of conceptual structure proposed by Jackendoff (1987). By providing the lexical representations of passive and causative morphology, it is claimed that the coincidence of affixal forms can no longer be regarded as a total accidental phenomena. The distinction between the gerundive UM and KI is discussed. The morphology of negative morpheme AN is also examined. It is shown that the difference in meaning between two negative types can make predictions about co-occurrence restrictions of the two negative versions. Finally, Chapter 5 summarizes the topics discussed and examines some consequences and implications. U of I Only ETDs are only available to UIUC Users without author permission