For the purpose of effective and reasonable development and utilization of bentonite from the Shangtianti deposit, the authors, starting with applied basic researches, carried out technological mineralogical studies of bentonite from the Shangtianti deposit. Mineral composition,structure and physico_chemical technological properties of bentonite were analysed; chemical composition, crystallochemical characteristics and interlayer charge of montmorillonite and their influence on the exploration and application were studied. Bentonite from shangtianti is Ca_Mg_bentonite and has characteristics of Cheto type ore. Montmorillonite has high degree of order and coarse crystal grains. As suspension capacity and colloid dispersion power of ores are rather low, bentonite can serve well as adsorption material. The main mineral composition of bentonite is Ca_montmorillonite, and the main impurity is cristobalite, characterized by fine grain size and uniform distribution and associated closely with montmorillonite, cristobalite is the main factor affecting purification. Technological process for purifying bentonite was designed on the basis of the above_mentioned factors. Finally, Na-bentonite of high purity was successfully prepared. The Na_montmorillonite content of the concentrate was 92.52%, and the yield was 36.87%. The pillaret montmorillonite experiments formed a product withd(001) value being 18.87°A (under the condition of calcination at 500℃), which, however, did not have a relatively large specific surface area. Based on bentonite, activated white clay was made,whose main quality indices attain or exceed the trade standards and other products of the same kind.