The characteristics of soil fractal dimension and its correlation with soil mechanical properties such as soil cohesionc,soil internal friction angle U and soil compaction in Karst area of central Guizhou Province were studied by means of field investigation and indoor experiments.The results revealed that the fractal dimension of soil in the research area w as usually between 2.80 and 2.93,while the fractal dimension would be greater than 2.90 if t he content of soil particle with diameter less than 0.002 mm exceeded 50%.Correlation analysis results showed that soil fractal dimension was positively correlated to soil cohesion and soil compaction,and the latter two increased with the increase of soil fractal dimension.How ever the soil fractal dimension was negatively correlated to internal friction angle,which decreased with the increase of fractal dimension.