With Hani terrace fields in the Quanfuzhang basins, Ailao Mountain in Yuanyang County as research area, this paper used the QuickBird Images as the input data for obtaining vector map of the distribution of terrace field plots. Arcview was used to calculate the box-counting dimension and information dimension of the terrace field edges. The results indicate that: （1) At four geomorphic unit scales, (a) the Quanfuzhuang basin, (b)the sub basin 21 and 22, (c)the terrace field patch 31, 32 and 33, and (d)the slope face 41, 42, 43 and 44, the side length (ε) of the box showed a significant linear correlation with the number of corresponding non-empty box N(ε), which reflects the property of their scale variance and demonstrates that the edges of terrace fields are fractal. （2) The shapes of terrace fields have a multiple self-similar structure, the degree of self-similar terrace field shapes are limited by the underlying terrains and their self-similar structural units are field plots.（3) At the largest studied scale of the Quanfuzhuang basin, the information dimension is the largest and the complexity of terrace field edges is highest; At the smallest scale of the slope face, the information dimension is the smallest and the edges of terrace fields are simple and the structures are clear. However, fractal dimension as a measure, independent of scale, to describe the characteristics of the patterns and processes still has some problems in the practical application.