Abstract: The oxidation experiment of Cr³⁺ showed that carboxyl terminated waterborne hyperbranched polymer (HBP-x) inhibited the oxidation of Cr³⁺ to Cr⁶⁺. And the effects of molecular weight and branching degree on the antioxidant capacity of HBP-x were investigated. In the experiment of pickling chrome tanning with white hide powder, HBP-x promoted the absorption and fixation of chrome tanning agent. The experimental results provided a good support for the application of HBP-x in clean leather making to promote chromium absorption and resist chromium oxidation.