Tone is an important phonological phenomenon in Oromo. Itrndistinguishes the meanings of lexical items and signals somerngrammatical functions. It has not been studied in detail so far. Thus,rnthe aim of this study is to describe and analyse it. The study isrnorganized into four chapters.rnChapter one presents a brief overview of the phonology. It alsornpresents the review of previous studies which are relevant to thernpresent study.rnChapter two deals with the significance of tone and its lexical andrngrammatical functions. It also presents toneless morphemes, floatingrntone and tone stability. In addition, it discusses the possible tonalrnpatterns in the language.rnChapter three treats tonal processes such as tone assimilation,rntone spreading, tone absorption and tone copying.rnChapter four presents the summary and conclusion of the study