Maguan karst landforms in the central Guizhou Plateau and Xichou fengcong－depression landscape in the southeastern Yunnan Plateau were chosen as the sample regions to study the fractal and geometry of karst depressions 21 closed depressions and 3 poljes have been developed in the Maguan area of Puding county,the average area of the depressions is 0.72 km², the mean edge number is 7.38 and the average perimeter is 3.41 km which is similar to the length of perimeter of 7 edge depressions.The fractal dimension of perimeter L(δ)with area A(δ)of the depressions is 1.23 and the dimension of edge number N(δ)and perimeters L(δ)is 2.928.64 depressions are developed in the area of 23.75 km² in Xichou fengcong-depression landscape;the average edge number is 8.27,the mean area is 0.371 km² and the perimeter is 2.448 km.In 64 depressions,54 have been captured each other and 129 edges have drifted more or less.The fractal dimension of perimeters L(δ)with the area A(δ)is 1.10,the dimension of edge numbers N(δ)and perimeters L(δ)of karst depressions is 2.938.The fractal dimensions are existed in the evolution processes of karst depressions and the depressions have the fractal geometry.