Abstract
The issue concerning the underlying representation of ü in Mandarin Chinese has been hotly debated since early 1940s. This paper makes an in-depth exploration of the question extending the scope to Chinese in general. A particle analysis is proposed to resol ve the unity and combination dilemma in the literature. Various phon ological processes and dialect comparisons pivoting on the temporal arrangement of the either iu or ui make the claims of a fixed vowel sequence untenable. Instead, ü is better treated as a single vowel segments which of two component particles i and u.