Abstract: This invention is related to the manufacturing process of the modified chromium sulphate used in the tanning process of the animal hides, and chromium tanning process performed by using the said chemical. This invention develops Manufacturing processes of chromium tanning chemical which do not require pickling and basification; Chromium and tanning chemical produced according to this process; and Chromium tanning processes which use the said chemical and do not require pickling and basification. As a result of the reaction of the chromium salts mentioned in the invention with mono and dicarboxyllic acids or salts of these acids, characteristics of the chromium salts change; thereby the invention provides benefits such as the elimination of the pickling and the basification process, minimization of the waste treatment burden and acceleration of the said processes in the tannery.