Abstract: This paper analyzes the character of stego-audio which is produced by Dither Modulation（DM） based hiding，an algorithm of QIM based hiding.A histogram is drawn with the absolute values of difference of transform domain coefficients from different segments of the stego-audio.Then a blind steganalysis algorithm for DM-QIM is proposed based on the character that there are some skip points in the histogram.The experimental results show that this detection algorithm is effective for both audio DM data hiding and audio simple QIM data hiding.