|Abstract In this thesis, a durational study and a tonal contrast study were conducted to investigate the tonal inventories in syllables with different rhyme durations in Nanchang Chinese, a dialect spoken in southeast China. The findings show that the tonal inventory is reduced in lexically stressless syllables, which have shorter rhyme duration. Nanchang is a Gan dialect spoken by about 4 million people in the city of Nanchang in Southeast China (Li 1995). There are five lexical tones in Nanchang, transcribed in a five point scale as 42, 24, 45, 213, and 21 (Hou & Wei 1998). Certain syllables in Nanchang are lexically stressless, known as qing sheng. Apart from lexical stress, Nanchang, like Standard Chinese, also has grammatical stress. The grammatical stress is introduced as the result of syntactic structures, for example, In Verb+Noun (VN) phrases, N bears grammatical stress as N is a nonhead in the syntactic structure, and in Noun+Noun (NN) words, the first N carries grammatical stress as it is a nonhead in the syntactic structure. This is known as the `Nonhead stress' rule (Duanmu 2007). According to Zhang's (2002) typological survey of contour tone distribution, the rhyme duration is the crucial factor that licenses contour tones (e.g. rising or falling tone). Thus, if the rhyme duration of syllables is affected by phonological parameters such as stress, then we expect the tonal contrast in syllables to be affected as well. This study examines whether different stresses in Nanchang have durational correlates, and if so, what happens to the tonal contrasts in syllables both with and without stress. The durational study of syllables with different stresses shows that grammatically stressed syllables have significantly longer rhyme duration than grammatically stressless but lexically stressed syllables, which in turn have longer rhyme duration than lexically stressless syllables. However, the size of the difference between grammatically stressed and grammatically stressless syllables is much smaller than that between grammatically stressless and lexically stressless syllables. With this finding, a tonal contrast study was conducted to examine the tonal contrasts in grammatically stressless but lexically stressed and lexically stressless syllables. Statistically, the five lexical tones in the grammatically stressless group were significantly different from each other in terms of both f0 average and shape whereas in the lexically stressless group, tones 42, 45 and 21 were neutralized and tones 24 and 213 also neutralized. In other words, the underlying tonal contrasts in lexically stressed but grammatically stressless syllables were preserved, whereas in lexically stressless syllables the tonal contrasts were massively reduced. The correspondence between the durational property of the syllable and its ability to carry tonal contrasts indicates that in order to understand the distribution of phonological contrasts, we must look beyond the pure phonological labels such as "stress" and understand the phonetic properties that the phonological labels entail.