Given a probability distribution, its corresponding information volume is Shannon entropy. However, how to determine the information volume of a given mass function is still an open issue. Based on Deng entropy, the information volume of mass function is presented in this paper. Given a mass function, the corresponding information volume is larger than its uncertainty measured by Deng entropy. The so called Deng distribution is defined as the BPA condition of the maximum Deng entropy. The information volume of Deng distribution is called the maximum information volume, which is lager than the maximum Deng entropy. In addition, both the total uncertainty case and the Deng distribution have the same information volume, namely, the maximum information volume. Some numerical examples are illustrated to show the efficiency of the proposed information volume of mass function.