The features of tones contact have been investigated between Xiang Dialect and Gan Dialect, by using the method of tone pattern in this paper. It is showed that the "transition" feature of the mixed dialect reflects in similar features of tones between mixed dialect and ancestor dialect or between mixed tones and target dialect,which includes as follows: the balance of the tone number, the mixing of tone category, the similarity of tone value, and the correlation of tone contour.