While the tonal features of Chinese isolated syllables are quite clear and well studied, tonal features of sentences are less well defined and thus scarcely analyzed. The present study utilizes an analytic and quantitative formulation of the process of fundamental frequency contour generation to decompose an F0 contour into its constituents: the phrase components and the tone components. Analysis of a number of sentences, uttered by two male speakers of Standard Chinese, revealed some important phenomena such as tone sandhi and phrasing. Prosodic structures, partially manifested by the phrase components, are often found to be different from the syntactic structures given by the generative grammar, but are believed to reflect the actual process of utterance generation.