Modification on time-scale and pitch-scale of Chinese syllable based on sinusoidal model is presented in this paper. Firstly,the short-term speech is decomposed into a sum of sinusoidal waves of different magnitudes and phases. Then vocal tractsystem and excitation are obtained using a homomophic technique.Lastly, the speech with desired time-scale and pitch-scale is obtained through the change of frequency and phase of excitation while the parameters of vocal tract system are changed accordingly. The results show that the adjustable scale of pitch and time-scale is big using this algorithm and it is suitable to be used in analysis and synthesis of Chinese speech.