The F0 contour of Chinese prosodic word is influenced greatly by the stress of its syllables. Based on the mathematical model to produce the optimized F0 contour ,this paper proposes a method of x2 fitting to optimize the continuity,the smoothness,the shape and the average feature of F0 contour of prosodic word,which can achieve the optimization of F0 contour under the function of the stress of the responding syllables.Based on the HNM speech synthesis system,we show the optimized results for the 64 to...