At the present time among the endangered species of plants, there exists elements of flora which can be found in Slovakia. Within the framework of the program "Protection of Endangered Genebank Plants in Slovakia" is the processing, existence and description of individual king nut ecotypes (Juglans Regia L.). Several agrophysical methods were applied for evaluating and grouping advantageous ecotypes in genebanks. This work presents the results obtained of the dimension and weight characteristics of fruits and shells, together with the determined necessary force for cracking nutfruits. The research was done on 16 selected samples obtained from 11 localities of southern Slovakia.