How to measure the uncertainty of the basic probability assignment (BPA) function is an open issue in Dempster⁻Shafer (D⁻S) theory. The main work of this paper is to propose a new belief entropy. which is mainly used to measure the uncertainty of BPA. The proposed belief entropy is based on Deng entropy and probability interval consisting of lower and upper probabilities. https://lecoureures.shop/product-category/ski-de-fond-homme-skis-classic/