In this paper attempted to define general character of karst forms occurrence and its sizes depending on mechanical (deformation and strength) properties of covering soil based on mass statistical analysis of data. As basic technique to defining of relationships between spatial distribution of karst forms, its morphometry and parameters of deformation and strength of soils applied author's methodic. The analysis completed on the example of 4 key areas, located on the territory of Permskiy kray. These areas are characterized with different conditions of evolution of carbonate and carbonate-sulfate karst. In the result were established lognormal spatial distribution of karst forms relatively to values of modulus of deformation and angel of internal friction. Karst forms have a normal spatial distribution relatively to values of cohesion of soil. Parameters of theoretical distribution laws are also defined. Determined trend to rise of mean diameters, heights of fractured zones and cavities, allocated in soil massif, with the increasing of deformation modulus and angle of internal friction of covering soil. Backward trend fixed for cohesion of soils and morphometry of karst forms. When cohesion of soil is high, sizes of sinkholes on the ground surface have a tendency to decrease. Based on trend-analysis and with application of special developed technique has been obtained prognostic equations for calculation of average expected sizes of different karst forms from known values of parameters of deformation and strength of covering soil.