Abstract: In view of the limitation of conventional methods,a DDPM method(detection of double pitches for Chinese Putonghua) is designed especially for detecting double pitches in Chinese Putonghua.It utilizes the quasi-periodicity in a short time frame of speech,and gets candidate pitches in every frame by using a searching algorithm.The double pitch contours are then determined from these candidates by virtue of the fact that pitch should change rather smoothly in consecutive frames.With the new method,a systematical investigation is made for detecting double pitches from various combinations of the four tones of Chinese Putonghua,both clean and contaminated with noise,achieving results that are quite satisfactory.The proposed method,of course,could be extended to general speech even continuous ones.