Mathematical structure of biological classification and its convincing interpretation have been an academic issue that has aroused extensive attention in the biological circle,but few have applied statistical distribution models to the study or analysis of structure of nonbiological classification,such as Soil Taxonomy.Comparison was made between the biological classification system for soil borne plant parasitic nematodes of the Tylenchina suborder and with a nonbiological one(Chinese Soil Taxonomy as an example)in biodiversity characteristics by calculating the power law distribution and Lognormal distribution of the two systems to analyze their similarities and differences.Results show that the two systems are very similar in mathematical structure and diversity characteristics,and both are reasonable information systems,which fit well to the same distribution models, such as power law distribution and lognormal distribution.Minor differences also exist between the two.The classification system of nematodes of the Tylenchina suborder is a branching system more profuse than the Chinese Soil Taxonomy.The latter seems to be more reasonable in designing in terms of evenness values.The Willis curves show that Chinese Soil Taxonomy has a more regular structure,which is probably related to difference in classification ideology between the two scientific disciplines.