Based on some chapters of the book “Pedodiversity” published by CRC in the US in 2013 and some other related references, a review is presented here of status quo of the study on pedodiversity and challenges it may face in future worldwide, with emphasis on research modes of the study on pedodiversity. Besides, this paper has a few paragraphs devoted to history, progresses major achievements and future challenges of the study. First of all, a brief introduction is made to how the concept of pedodiversity was initiated and connotation of diversity：(1) The exploration of the concept of diversity should proceed from the angle of practicality and the concept should encompass species diversity (or richness) and distribution of individuals of the (evenness or uniformity); From the point of view of methodology, the most popular methods for diversity analysis may be grouped into two general classes: indices of richness and object abundance models. (2) To the knowledge of the authors, the first pedologist who tried to analyze and quantify pedological diversity of a region was a Russian, V. M. Fridland. Regretfully his work did not arouse any attention from his colleagues in the circle. Then at the beginning of the 1990s, Ibáňez and his coworkers adopted the mathematical tools developed by some ecologists in studying soil diversity, created a neologism, “pedodiversity” and then published a number of papers, explaining the main measuring methods used in analyzing soil diversity or pedodiversity, which, as a matter of fact, triggered an expedition to explore theories of and methods for soil diversity theory. Then attempts are made to elaborate objectives and methodology of the pedodiversity analysis, including some fundamental principles, like diversity vs soil classification systems, scale vs sampling intensity. Nowadays, the USDA (United States Department of Agriculture) Soil Taxonomy is being used by pedologists the world over, and at the same time, WRB (the Word Reference Base for Soil Resources), developed jointly by the International Union of Soil Sciences (IUSS) and FAO and later pedologists the world over, has been accepted as a universal soil classification system. In addition, the measurement of pedorichness and pedodiversity depends on methods and scales of soil classification and sampling intensity. And next, analysis is done with emphasis of major models currently used in the research of pedodiversity, such as Willis curve, soil diversity vs biodiversity, abundance distribution models, diversity-area relationships, diversity-time relationships, diversity nested systems, diversity vs pedogenetic processes, diversity vs landscape evolution, etc., of which some are elaborated in detail: (1) Willis curve:The Willis curve has been proved to be able to embody the distribution nature of all biospecies. It originates from the array of taxonomic groups in line with the variation of abundance from the maximum to the minimum, appearing in a concave-shaped curve of frequency distribution. (2) Soil diversity vs biodiversity:Several studies have found strong correlations between pedodiversity and biodiversity under different environments and at different in some regions, and between pedodiversity and landform diversity, too. Furthermore, the relationships of biodiversity of various species groups with lithological diversity and climate diversity have also been demonstrated. (3) Abundance distribution models:The distribution of the numbers of species within an ecological community has long been regarded as a critical aspect in the study of community structure. The most commonly used models include geometric series, logarithmic series, log-normal distribution, "broken stick" (robust) model. Researches show that the same regularities do exist in categorical distribution of soils. (4) Diversity-area relationships:The pedodiversity-area relationship fits a power law and has nothing related to the type and scale of classification. It has been demonstrated that in a given archipelago or other spaces, the power law function value of the index of discontinuours objects index is generally around 0.25. (5) Diversity-time relationships:In a natural area free of human activities, species diversity improves with the time passing on and so does pedodiversity. In the end, as soil is essential to human survival, pedodiversity preservation merits special attention, perhaps more than other natural resources. Nowadays, the pedosphere and many of its soil types are on the edge of extinction as a result of intensive and widespread impact of human activities. Moreover, the impacts on land, soil resources and eco-environment are intensifying more and more significantly with the time going on, and land degradation, industrialized farming and orderless urban sprawl are the main driving forces of changes in and loss of pedodiversity.