Abstract: The limed cattle hide pelts were delimed with ammonium sulfate, low-ammonia deliming agent (ammonium sulfate 25%), boric acid, boron-containing deliming agent (boric acid 50%) and adipic acid. The results showed that ammonium sulfate, low -ammonia deliming agent, boric acid and boron -containing deliming agent formed pH 8 -9 buffer systems after reacting with lime and alkali in limed pelts because the pKa values of ammonium sulfate and boric acid are 9.2. Additionally, they penetrated limed pelts fastly and produced soft delimed pelts. Adipic acid did not form a buffer system of pH 8-9 during deliming due to its pKa of 4.4. Moreover, adipic acid penetrated relatively slowly, and the delimed pelt obtained was not soft enough. These results suggested that fully or partially using acidic components with a pKa about 9 is of great significance for development of ammonia -free and boron -free deliming agents with better performance.